Seina Yamada/Masaki Jurai (山田 西南, Yamada Seina) is the main character of the Tenchi Muyo OVA spinoff, Tenchi Muyo! GXP. Due to being "blessed" with the worst luck in the universe, a series of mishaps happen that lead Seina into joining the GP. He quickly becomes captain of his own ship and is on his way to many adventures throughout the galaxy. He also appears in OVA 4 and 5 and as a major supporting character in the Paradise War novels, using the alias Minamida
Tenchi Muyo! GXP (anime)
Seina Yamada is a 15-year-old boy at the beginning of the series. He is lifelong friends with Tenchi (who he addresses as 'Tenchi-Sempai'), Kiriko Masaki, and Kiriko's brother Kai. Before joining the Galaxy Police, Seina lived on Earth with his parents who run a small grocery. Due to the strong resemblance between Seina, Tenchi & Kenshi Masaki, Seina is likely a distant cousin of theirs, but none-the-less does not carry the 'Masaki' family name (though after the events of episode 26 of GXP, this may have changed).
Aside from Tenchi, Kiriko, and Kai, Seina has very few friends; mostly because he has what seems to be the worst luck in the universe. Minor disasters often occur in his presence, and anyone near him stays a good distance away from him. Seina's usual (lack of) luck almost ends when a spaceship nearly crashes on his head at the Masaki residence. Its driver, the beautiful Galaxy Police Detective Second Class Amane Kaunaq, had meant to present Tenchi a pamphlet for joining the Galaxy Police, but mistakenly offers Seina the application instead, under the impression that Tenchi was training the boy.
His family persuades him - via forcibly nabbing his signature and thumbprint - to fill out the application, with the hope that Seina would win a prize. When he wakes from sleep for the night, he finds himself aboard a spaceship, recruited to be the newest member of the G.P. Academy. He also meets Mitoto, the ditzy mother of Mihoshi and teleporting cleaning lady extraordinaire, before discovering his friend Kiriko is also a GP officer. From there, Seina is thrown into a plan to stop the Daluma pirate guild from taking over the galaxy.
Initially, Seina's entrance into the GP was being fought against because he is apart of an underdeveloped planet (Earth), though he had the extremely helpful backing of galactic political figure Seto Kamaki Jurai (aka Lady Seto, the "Devil Princess of Jurai"), who took an instant interest in the boy. Lady Seto's interest in Seina comes from the fact that his luck attracted a large fleet of space pirates whom the GP was able to capture after dodging arrest for years. Seina also gained the backing of GP Board Director Airi Masaki. Initially, Kiriko is dead set against Seina staying with the GP out of her protectiveness for the boy, though she eventually relents while still being cautious with Seina remaining in space.
When Seina's bad luck was found to have an effect of attracting space pirates, the G.P. capitalized on it by placing Seina in command of one of the Decoy Fleet's newest ships, the Kamidake . However, when the ship was irreparably damaged as a result of an encounter with space pirate Tarant Shank, Lady Seto then presented Seina with a ship designed by the greatest scientist in the universe, Washu, which was named the Kamidake II by Seina. The ship consists of the main ship body, subspace interiors and a cabbit (cat/rabbit-like creature who acts as a biological computer unit) similar to the legendary Ryo-Ohki, named Fuku by Seina, meaning good luck, the complete opposite of Seina. Later, the ship became a hybrid, when under Lady Seto's supervision, it was fused together with Kiriko's second-generation Juraian Royal Tree Mizuki (enabling it to generate Light Hawk Wings for protection). The main pod, which houses the royal tree in a Juraian Royal Tree ship, was used for the fusion.
Much like Tenchi, all of the girls in Seina's new out-of-this-world life; Amane, Kiriko, child-like high priestess Neju Na Melmas, and gentle former space pirate Ryoko Balta, all fall for Seina and fight for his attention and heart.
Kiriko's love for Seina comes out in the open after basically having a hand in raising him, though at times she feels inadequate to the other girls; Amane, in the beginning, used Seina as the butt of her jokes and used her sex appeal to play pranks on him and to push Kiriko and Erma's (who was really Ryoko in disguise) buttons, but gradually gained true feelings for him. Ryoko, a noble and infamous space pirate (named after Ryoko Hakubi), also fell in love with Seina after running into him again and again throughout space because of his magnetic attraction to space pirates. After the Daluma Guild situation, Ryoko quit being a pirate and vowed to serve Seina for the rest of her days and was allowed to join the G.P. and the crew of the Kamidake; Neju, a 2000-year-old high priestess (though her age was frozen as a 10-year-old girl until leaving her position), considers Seina her big brother and challenges the other girls for his attention. She continuously claims that she intends to marry Seina when she "grows up." Being that she is a target for kidnapping and assassination, it was decided that she would join the G.P. Academy and train aboard the Kamidake under Seina.
Battles with pirates and resulting revelations (mainly anime)
During the time Seina commanded the Kamidake and Kamidake II, he was earning an equivalent to a fleet commander's salary. However, because he was still a cadet, that money is being managed by Kiriko (his defacto guardian) and kept in a special account until he graduates and comes of age. However, the interest of the money accumulated was forwarded to his family on Earth. It was so much money that the Yamada family used it to build a huge new home, as well as building a huge supermarket in place of their small grocery (which also blossomed due to is bad luck no longer affecting it). When Seina brought his crew and other visitors to visit they all also helped inprove the store with product advice and accounting help. In the novels, his income was further enhanced by the bounties Seina was being paid for capturing so many pirates and a reward for unknowingly capturing Widow, the galaxy's most infamous serial killer. His personal balance has surpassed the budgets of entire planets and Seto's people borrow from him to settle Juraian matters, repaying it at a decent interest rate. According to accountants that handle Jurai's finances, by capturing so many pirates and becoming a galactic financial power, Sena has boosted the economy of the entire Galaxy Federation almost single-handedly.
Late in the series Seina had to rescue the kidnapped Fuku from a planetary secret base of Tarant Shank, who had teamed up with rogue elements of the Galaxy Army. At this time he encountered a Wau tribe, who declared him to be a prophecised "Legendary Hero" and threw him into their "idol," an ancient mecha (which is Zinv of Dual! Parallel Trouble Adventure). Seina was able to activate the mecha, which he used to save not only Fuku, but also cabbit clones made from Fuku's cells by Tarant's scientists. Angered by what was done to the clones (other than being captured, one had been killed and dissected), Seina fought Shank and his allies. But in doing this, the mecha was able to integrate itself to the Kamidake II (rejuvenating its ancient and decrepit frame), which had been captured with Fuku. And even more startling, the mecha formed Light Hawk Wings, which are usually generated by the Juraian Royal Treeships, even though it was not bonded with Mizuki.
Afterward, it was revealed by Emperor Azusa, Empresses Funaho and Misaki that the mecha has as its power source, an age-fixed first-generation Jurai Royal Tree seed, with the seed bonding itself with Seina. As a result, Seina is now third-in-line to the Jurai throne, behind Prince Yosho (Tenchi's grandpa) and Tenchi. Thus, a marriage between Seina, Amane, Kiriko, Ryoko, and Neju was arranged for political reasons. Seina is initially very disposed against what he thinks is an attempt to force the girls into marrying him, but is later persuaded otherwise after he learns that they are doing so out of their own free wills and genuine affection. After two years in the Galaxy Police Academy, Seina's wedding is held on a spaceship near Earth's moon.
However, before the ceremony could begin, two incidents occurred. First, Shank broke into Seina's dressing room, hoping to kill the boy. Luckily, Shank's impatience gets the best of him and Seina was able to subdue him. With him helpless, Seina could have finished him for good (he had ample reason to hate him-especially in the novels) but he turns him over to the police instead. Also, Seto's ladies-in-waiting - Gyokuren, Hakuren, Karen, and Suiren - who were actually agents of the Renza Federation seeking to use Seina's abilities to rid their home from marauding pirates, kidnapped Seina into their small ship and began to molest him in a public broadcast to ensure their non-Galactic Union organization's survival. As a result, the four are included into the marriage, or at least the crew of the Kamidake II, as it patrols for pirates and illegal activities in space (although the 4th episode of the 4th OVA confirms that Kiriko, Amane, Ryoko, Neju, Gyokuren, Hakuren, Karen, and Suiren are all his wives, the GXP novels reveal the interruption prevented even the first marriages, initially.
Only in the GXP Novels
Masaki Kajishima (the original creator of Tenchi Muyo!) wasn't pleased with the work done on the GXP anime. As such, he began writing the GXP story in novel form. The novels are canon and Seina seems unchanged. The novels follow the story closely with minor exceptions, mostly that the novels simply go much more in-depth than the anime, expanding on and adding characters. As of 2020, fan-produced translations exist of Volumes 1-16 of the GXP novels, with a machine translation of volume 17 available.
It is better shown in the novels how Seina can inherently sense and deal with oncoming danger. Sometimes using it to his advantage to catch others in his misfortune. His trouble avoidance abilities have given him extraordinary reflexes.
In the novels, the nature of the NB robot assistant was much different, affecting how Seina dealt with it. NB, at its core, really was only a robot assistant made by Airi, although a very sophisticated one that could transform its shape. Bothered that it originally used Airi’s voice, Seina did give it a Kansai accent. Perverted actions, including some used in the anime, were solely due to being controlled directly by Airi. The AI Kirche could also control NB. NB actually self-destructs after Kirche leaves it in the 14th volume
Kirche was a digital AI with an astral who had been a TV personality. When Seina’s biological data was scanned by Erma’s group and it wreaked havoc with the Federation’s computer systems, one of the things that happened was that a digital version of Seina, created by the system, kidnapped Kirche. She actually saw this as him saving her from her unhappy existence and fell in love with the real Seina. She then hid inside his NB to be near him and able to communicate with him while he dreamed. Although he could not remember her after waking, meeting her in his dreams help calm his many anxieties.
On the same night his digital information was was released he also encountered the sociopathic serial killer Widow. She was planning on killing Seina, but while talking to him, and being "saved" by him from a nearby accident (partially due to his bad luck), his inherent purity instantly transformed her and she decided she would completely devote herself to him. Knowing that it was the only way she could be worthy of him, she willingly turned herself in to answer for her crimes, declaring that Seina had captured her. She confessed to any crimes she could recall (she had been active so long she couldn't remember everything, not even her original appearance before changing it. Her crimes were so heinous (even being responsible for the collapse and the deaths of almost everyone on Airi's home planet) that she was soon put to death. But her devotion was so strong that Washu devised a way to capture her astral (devoid of her memories or killer tendencies) and used it as the core astral in Fuku.
A major motivating factor for Seina in the novels was also his introduction to and the apparent death of Miki Steinbeck, a senior of his in the GP Academy. Soon after meeting her she went on a training mission and the station she was at was attacked by Tarant Shank, who left no one alive. What only Miki's father knew, however, was that she was an AI with an astral stored in an artificial body that he had created. When she was freed from her artificial body by its destruction, she first tried to send herself in a transmission to Seina's NB, for a moment it transformed into her image and tried to talk to Seina, but Kirche, already inside, was surprised and refused access to her astral. She then inhabited Shank's computer systems, sabotaging his efforts from inside while eluding detection. Seina was not told initially that she was an AI and the entire experience shook him badly.
Seto's ladies-in-waiting - Gyokuren, Hakuren, Karen, and Suiren are extremely minor characters without much personality in the anime but are constant major supporting characters in the novels and central to the plot that follows what the anime adapts. They are all royalty in Renza and all marry Seina, in part to unify their federation and the galaxy.
In the novel, when Seina activates ZInv, he also finds the sleeping AI astral of D, from Dual Parallel Trouble Adventure. She helps him understand what ZInv is and can do. Her AI is degrading however and perilously attached to the aging and decrepit Robot frame.
This enhanced connection to Dual presented in GXP may be the novels most important addition. In it, it is revealed that Kazuki and his group were progenitors of "The Great Prehistoric Civilization" and their initial adventures took place on an Earth identical to the current one, but existing about a billion years before. In relation to Seina, it is shown that he is actually the reincarnation of Dual!'s protagonist Kazuki Yotsuga. It is also shown how all his wives, and probable future wives, follow a repeating astral pattern that correspond to those of Kazuki’s romantic partners in that series, Mitsuki Sanada, Yayoi Schwael, Mitsuki Rara, and D. A couple characters have much more direct relationships to the earlier group. It is revealed that Miki Steinbeck is the direct reincarnation of Mitsuki Sanada with the exact same astral (her father/creator is also the reincarnation of Ken Sanad and Tsukiko Masaki’s first husband is implied to have been the reincarnation of Hiroshi Rara). D is essentially the exact same character, her astral preserved as an AI and all her memories from a billion years ago remain preserved, only her outer body has changed. Other direct reincarnations or surviving astrals have not yet been revealed.
As hinted at in the anime, Washu confirms that Fuku has the ability to transform into a human form once she is mature enough. What is changed in the novels is that Fuku’s clones, shown near the end, all become attached to the astrals of Miki Steinbeck, Kirche, and D, aided by Doctor Clay who was freed by, and working for the Shank Guild and the GXP Army group but double-crossed them when Miki offered a better deal. Access to the Shank Guild's expansive scientific research. Although the Shank scientists were unable to replicate Fuku's powers in the clones, Washu was able to give body enhancement to all of them so that they could transform into humanoid forms replicating their previous bodies, or digital appearance in the case of Kirche. They can also now control the Kamidake II, although Fuku always takes precedence. D is introduced only in the chapters right before. They are also likely to be the third set of Seina's wives.
In the novels, Washu confirms that Tenchi has unconsciously given Seina, and anyone really important to him, near immortality. Seina's words of support were actually a major influence factor in getting Tenchi to accept these side-effects of his almighty powers. Tenchi was worried that his own insecurity about living an endless existence alone, granting the same to his loved ones so it wouldn't happen, would be a burden to them. Seina tells him something along the lines that if everyone worked with each other and stayed together, the length of time they will spend living (which is obviously going to be LONG) will be a happy one and not a sad one as happiness depends more on how they use the time they have. Tenchi is relieved by Seina's words and resolve and feels some of the weight burdening his shoulders being lessened.
GXP novels, Part Two
Starting with Volume 15, the novels chronicle what happens after Haruken's group kidnapped Seina and brought him to the Renza Federation. Zinv is venerated there as the original model of their own mecha. Some also venerate Seina as its master, others see him as a false master of a robot that should rightfully belong to them. Haruken's group wants Seina and Zinv’s help with defeating their pirate problem, led or aided by HIMIK, this universe's version of Zinv's counterpart in Dual.
In Seina’s case, he has had very little to do with space battles so far. Instead he has had to mainly deal with magic and fantasy elements found in Renza.
The commanders of the forces that will be fighting the space pirates are all magical races. Souren, the commander of the entire fleet, is a male elf that Seina mistook for a female and still gets confused about. Sajyu, a seductress dryad and captain of the group's flagship, and Kaguya, a pilot and leader of the mecha knights he will be teaming with.
After being forced to fight HIMIK early on, both came out badly. Seina was able to badly damage HIMIK but also has to randomly jump to avoid his and Zinv’s destruction.
Damaged and needing repair, Seina decides he needs safe harbor. He knows he could contact Kiriko, or try to contact Washu (she never answers his messages) with his Philosopher's Stone (his new personal assistant, created by Washu and implanted in his skin) but is afraid of who else might hear. He studies where he jumped to and realizes he is close to a planet, Barrium, where Souren told him his sister, Airen, is stationed. He travels there and lands in a forest to hide Zinv in a lake. What he didn't count on was that it was a magic planet or what that would mean. Goblins immediately start chasing him and then is attackked by a chimera, all while quickly developing a high fever and getting very sick. Luckily, a dwarf named Barigaru takes him in him. While he stays there he becomes able to perform magic himself, gaining a tremendous capacity for it.
Also, his Philosopher's Stone, thanks to magical interference, develops a mind of its own. It develops a personality and probably an astral. Only Seina can see, hear, and even feel her. Seina calls her Natori and she becomes his assistant in helping him learn magic. She, like almost every girl he meets, immediately declares her interest in him.
It is hinted at the end of volume 17 that Barigaru is considering hiring Jovia Jovis to teach magic to Seina.
Tenchi Muyo! Ryo-Ohki OVA 4 and 5
In the last episode of OVA 4, Seina takes a break from his time in Renza and, along with Amane and Gyokuren, visit Tenchi as they (mainly the women) discuss what to do with Kenshi’s fate. By this time he has married all the girls in both Kiriko’s and Haruken’s groups.
OVA 5 takes place immediately after Seina’s time in Renza and Tenchi and his group invite Seina’s group to build a house next to theirs and make their official home there on Earth. The events of Paradise War take place between episodes 2 and 3, Lady Seto and the Galactic Federation charge Seina with overseeing a plan to unite the fractured pirate guilds in the Galactic Federation into a governmental federation of its own, with its own territory. Seina appears with their cast in episode 3.
In Paradise War, Seina assumed the pseudonym Minamida, an anagram of the characters in “Seina Yamada” (as pirates would be wary of the man that splintered them in the first place), and oversaw a proxy war made of representatives of the various pirate guilds and Shou Kukoma, Earth’s representative. The agents of the most powerful pirate groups were Dird Shank, Alea Balta, Apuesta Daluma, and Palty Jurai. The proxy war took place on a tropical island on Earth.
Seina organized their battles and made sure nothing goes wrong. He and Zinv also guarded the island from outside interference while the proxy war was being held. In the end he also revealed the secret of the island, relinquishing authority to the victor.
He was accompanied by Fuku, Miki, D, and Kirche, who made themselves unassuming by appearing publicly as cabbits with white fur.
Lovers List and Bad Luck Reversal
Seina’s probability bias somehow attracts women with the astral patterns of Kazuki’s previous partners and they are inevitably charmed by him. When girls with all four patterns are grouped with Seina, they are able to lessen or cancel out his bad luck, often turning it into good luck.
This chart is adapted and greatly expanded from one made by Washu, revealed in the novels. Names and spaces that are italicized are from this initial list.. The table headers are added, the rest are new additions, some merely speculated, their positions in relationship to the astral patterns may change:
|Astral =||Mitsuki Sanada||Yayoi Schwael||Mitsuki Rara||D|
|Group 1:||Kiriko Masaki||Amane Kaunaq||Ryoko Balta||Neju Na Melmas|
|Group 3:||Tsukiko Masaki||Mikami Kuramitsu||X||Mirror-Seto (Kuis Panta)|
|Group 4:||Miki Steinbeck||Fuku||Kirche||D|
|Group 5:||X||X||Ringo Tatsuki||X|
|Group 6:||Mikage(?)||Maya(?)||Acha||X (child)|
|Group 7:||Minaho Masaki||Mizune Masaki||Otoka Masaki||Fuka Masaki|
|Group 8:||Airen||Sojyu||Souren ? (sex-change?)||Kaguya|
|Group 9:||Natori?||Jovia Jovis?||X?||X?|
To further clarify the feelings of some of those listed:
There might still be others that have been mentioned in passing or hinted but as of the present, these are the women/girls who are implied to be on the line-up of Seina's wives-to-be.
Airi Masaki is more or less implied as an unavoidable case (much to Seina's fears) but this is also considered a running gag. It should be pointed out though, Airi was very much part of his life when Washu made her list, and she didn't include her. Also, when Seina went on a vacation to beach planet Imuim with a large group of women, all of whom are on this list, Airi was specifically excluded (and sent on a separate vacation with Yosho).
Tsukiko Masaki, Kiriko's mother, was seriously thinking of marrying Seina before he left for space. She genuinely loves him but it was also a logical decision because, as he grew older, his bad luck would make it impossible to live in largely populated areas and only those in Masaki Village would be likely to handle it. She looked forward to being his support. She now has been forced to defer to her daughter but has not given up.
Mikami Kuramitsu started having feelings for Seina after he unknowingly defeated Widow. As the Academy principal she uses a façade of composed elder authority but she is actually young in appearance and her true personality is also much more mischievous and flirty. After he graduates she feels more able to pursue him.
Mirror Seto/ Kuis Panta used to be, basically, just a facet of Lady Seto, with the same memories and shared existence, but upon meeting Seina (as Seto) when he was a young boy she started keeping her memories of him blocked from her other half and started to develop her own separate personality. She tells him her story and confesses her love to him a little before his planned wedding ceremony with Kiriko’s group. She also asks Seina to give her a new name, as she considers him to have “given birth” to her new identity.
Ringo Tatsuki leads the accounting division of the Jurian fleet and is a personal advisor to Seto as well as in charge of Seina's finances. She began only being impressed by his achievements in space, and thankful for the fiscal surpluses he created (and she was greatly responsible for the immense monetary rewards he received) but she eventually started developing feelings for him, especially after spending vacations with him and the other girls on Earth and Imuim and during an incident where she was trapped alone with him in a private house, taking care of Mikage together.
Acha a Wau child with golden fur seen briefly in the GXP series whose role is expanded in the novels. She considers Seina to be the legendary hero of her village and he personally saved her from pirates and helped gather medicinal herbs to save her mother. It is made clear that the village that housed Zinv has “given” her, their young sacred maiden, to Seina as a wife (and would not be welcome if he refused her). While Seina is away, she is being taken care of, at least partially, by Mitoto. She lives at the Galaxy Academy and is going to school there.
Maya is a daughter of Makihi, leader of the dancers and entertainers on Racepshi. She is tasked with, and is very willing, to seduce Seina and have a child with him to expand the talent of the family. At one point she performs a silhouette dance solely for Seina, which is supposed to do the trick. Seina is charmed by the dance but refuses her further advances, she believes it’s because she isn’t a talented enough dancer yet but truthfully, he has no problem turning her down as she is still a child to him.
Minaho Masaki has declared in a novel that she will pursue Seina after conversing with Emperor Azusa and Empress Funaho. Azusa has also bluntly and suddenly offered her to Seina in conversation. While her three Masaki members, Mizune, Otoka, and Fuuka, mention in the Dai-Yon Ki OVAs that they are specifically included as well completing a team of four women.
Mizune Masaki, Otoka Masaki, & Fuka Masaki all originally came from Masaki Village on Earth and know Seina from their time spent there. They have become Minaho’s assistants but because Seto didn’t want to surprise and overwhelm Seina with the sudden appearance of people he knew from Earth, they have been prevented from seeing him. They actually work behind the scenes protecting Seina. They have not expressed great affection for Seina yet, but it is heavily implied they are at least set in become his wives in a political marriage for Jurai.
Conditions to reverse Seina's Bad Luck:
- He must be with four women for the change to perfectly take effect. They can be women from different groups but they need to correspond with the four different astral patterns. In other words, the change in luck doesn't happen properly if the four women with him consist of multiple reincarnations of the same heroine. E.g. A team of Kiriko, Karen, Miki, Minaho will not work as they all trace the same personality/astral pattern/reincarnation of Dual!'s Mitsuki Sanada.
- As more of the women who matches the pattern gather around him, the more it positively effects him and maybe even the galaxy itself. Seto and Washu have been identifying more and more women who match the criteria and including them into teams. Marrying them can be considered as more than merely political, it could genuinely be considered for the greater good.
- It almost seems any woman Seina meets could be a possible bride but occasionally some possibilities seem to have been eliminated. Tennyo Masaki, Tenchi’s sister, is like a sister to him, a little like another mother too, as she impersonated her mother occasionally while taking care of him as a child. Airi Masaki is seen as a horribly inappropriate grandmother to him (though he would never call her that to her face) and he is constantly bothered by her behavior.
- Seina was visiting Tenchi when Kiyone died. Because of this, Seina feels, at least suspects somewhat, that her death may have been his fault.
- Seina has been diagnosed to have a complex about women due to his bad luck. He grew up with a mindset that doesn't think women would find him attractive even the tiniest bit and he is numb to the romantic intent behind the advances of the women around him putting it off as just them teasing him or toying with him. It took a lot of effort into the main female characters' part to get him to start overcoming this complex. This event happened during their paid vacation on the resort planet that was shown in the anime with the details mentioned above completely taken out of the episode's contents.
- Washu has stated that she cannot cure Seina's probability bias without Tenchi removing his protection from him, but if she did, it would probably destroy at least two galaxies.
- When Seina was born, a massive storm appeared out of nowhere, causing a blackout, and massive problems in the area.
- Seina has episodes where he recalls Dual!'s Yotsuga Kazuki's memories as his own. This is because he is essentially the same soul just reincarnated billions of years after Dual!.
- At one point, it is suggested the Seina's bad luck is because of the events at the end of the Dual! anime, the dividing and remerging of the timelines.
- D has mentioned that Yotsuga Kazuki had a better figure than Seina. This can be assumed to be due to Seina growing up suffering from a lot of repeated injuries affecting the shape his body grew into.
- Even before delving deep into the connection between GXP and Dual! it has been mentioned in the novels that Seina likes curry (especially one made by Tsukiko) which is also Kazuki's favorite food.
- The Yamada Family business is actually much larger than how it was shown on the anime when Seina returned home for a visit. In the novels it is described that their business is large enough to the point of building their own shopping mall and having their own company car, even gathering the unwanted advances of competing chain malls in the region. Their employees also consist of some if not many people who are from space. Ringo Tatsuki sometimes deals with their accounting needs (much to their competitors' bad luck).
- Seina gains magical powers in some of the later novels, after crash landing on a magic planet, and developing a magic organ. It is stated he is enormously powerful.
- In the GXP novels, after Kirche is removed from NB, Washu gives Seina what is called a Philosopher's Stone, that is an AI directly implanted into his body, that has a direct link to Washu's databanks.
- While on the magic planet, it developed a personality of its own, though no indication it has an Astral as of yet..
- Had Seina not gone to space or married Tsukiko, he would likely have become a hermit living in the mountains in order to protect people from his bad luck.
- By recognizing when something bad will happen Seina can trap others in his bad luck's effects. He has trapped pirates in a landslide he started and other pursuers in a forest trap he set off. Because he has trained himself so well to deal with his own bad luck he always escapes practically unharmed.
- In the GXP novels, Washu states that most people with bad luck as great as Seina's don't live for very long after birth.
- The reason he has survived so long is because he has developed a very strong ability to react, as well as a sense of danger.
- Washu also states Seina has a weaker level of 'positive' probability bias (aka good luck) that, while it cannot negate his bad luck gives him just enough of a chance to survive, or be saved.
- Seina Yamada's name (山田・西南 Yamada Seina) lit. translates to "Southwest Mountain Field".
- Seina has two known nicknames; "Sainan" (災難, lit. "disaster/calamity/catastrophe ", on Earth), and "Lorelei-Seina" (ローレライ・西南, lit. "Siren of Rhine Seina") as a nod to the sirens of legend, and to Seina's ability to attract and even plague pirates.
- Volume 9 Chapter 12