As Fuku is unable to handle the stress of combat, Seina, Amane, Kiriko, and Ryoko create a sub-system allowing them to control the Kamidake without needing her, but this makes Fuku feel neglected and she becomes very sad. She then experiences a happy memory of her time with Washu and Ryo-Ohki and decides to head back to Earth while nobody is on the ship... except for Seina.
Full Recap
The crew of the Kamidake sees Neju off as she boards another ship, but Fuku is visibly saddened to see her go away.
Their next mission sees them engaging in combat with a fleet of pirates. However, Fuku panics during the fighting and causes the Kamidake's systems to malfunction and power output to drop. Amane angrily tells Fuku to get a hold of herself, while Kiriko has to switch the ship's controls to manual.
Back at Amane's mansion, Amane, Kiriko, and Ryoko discuss what happened with Fuku. Kiriko says that there's nothing they can do about her since she's still a baby. Ryoko, however, doesn't like how their ship's abilities rely on her emotions.
Just before their next mission on the Kamidake, Seina gives Fuku a bath and apologizes to her, saying that he wouldn't make her fight if it weren't his job. However, Fuku again panics during battle despite encouragement from Kiriko and Ryoko, and the ship flees from the enemy.
After the battle, Seina tries cheering up Fuku despite messing up again. But now, Kiriko tells Seina that she and the others believe they should build a sub-system that would allow the crew to operate the Kamidake's systems without needing Fuku. She explains that not doing so would jeopardize their mission and put Fuku in extreme danger, and Seina reluctantly agrees with her.
Seina puts Fuku to sleep and tells her that they're only building the sub-system for her sake. The next day, they strap Fuku to a device that records data for the sub-system while Fuku performs training exercises. They collect all the required data, but Fuku finds that everyone is too busy to give her any attention. Ryoko then tries getting her to eat, but she won't have any. Seina notices and thinks she's sick, and he holds her and pats her, reminding Fuku of a happy memory of someone else caring for her in the same way.
Fuku enters the bridge the next day carrying her favorite orange blanket, but Kiriko takes it away because it's dirty. She and Amane then happily tell Fuku that they won't be needing her in a few days, but this only brings Fuku to the verge of crying. The first test of the sub-system proves to be a resounding success.
Fuku returns to her room but doesn't know where her blanket is. Kiriko comes in and gives her a different, clean blanket, but after Fuku sniffs it, she realizes she doesn't want it, and she doesn't want to sleep in her bed, either. She wanders around the ship and ends up in one of the seats on the bridge. Seina comes along and finds her, holding her in the same way he did before. He sets her down and goes to work on some systems that he notices need repairing. While he's busy, Fuku experiences the complete version of her memory from earlier: Washu, her creator, rubs her egg while Ryo-Ohki looks at her curiously. Washu shows the egg to Ryo-Ohki and says that she can consider Fuku to be her sister.
Fuku becomes very happy from this memory, and now she wants to see Washu and Ryo-Ohki again. So she powers up the Kamidake. Seina wakes up after a nap to keep working, but he's shocked to find that they're in space instead of being docked at the Galaxy Academy. He tries running to the bridge, but the entrance is blocked, and Fuku looks unresponsive.
Meanwhile, Airi summons Amane, Kiriko, and Ryoko to her office upon learning that the Kamidake is missing. She is also aware of the sub-system they created and explains to them the real issue with Fuku is that they treat her only as a malfunctioning computer and don't give her any attention. She suggests they need to embrace and give her more love to get her to trust them.
Seina keeps trying to convince Fuku to open the entrance, but an explosion rocks the ship, and Seina manages to get inside only to find a massive pirate fleet that's firing at them.
At the same time, Alan, Barry, and Cohen are sitting in their prison cell on one of the pirate ships. Alan and Cohen don't remember why they're there (despite Alan being the one who arranged for them to become prisoners in the first place), and Barry is still crying over Naoko. Thankfully, a pirate woman comes along and tells them their meal will come late due to them being in combat mode, and a look at her white panties raises their spirits.
Mikami suggests to Airi that Fuku is likely homesick and returned to Washu. Amane, Kiriko, and Ryoko then attempt to locate the Kamidake upon realizing that Seina is onboard. Kiriko manages to find it, but they're too far away to organize a rescue fleet large enough to combat the pirates. Thankfully, Amane knows of a secret Juraian supply base near there thanks to Mihoshi, and they attempt to use the teleporter in Airi's office to get there. However, they are over the weight limit and try taking off all of their clothes bar their underwear, but the weight problem turns out to be NB, who is now attempting to take pictures of their exposed bodies. Amane kicks NB away, allowing them to teleport.
Amane speaks with Lady Seto and convinces her to lend them the powerful warship Chobimaru—commanded by Mashishu Kuramitsu—saying that she owes them for making them transport the Original J and Neju. Seto agrees, but on the condition that they no longer call in favors after the fact.
The Chobimaru reaches the Kamidake's position, but while Amane, Kiriko, and Ryoko are now angry that pirates are harassing Fuku, they can't use the Chobimaru's weapons because the Kamidake is too close to the pirate ships. Seina manages to calm Fuku and tell her that he and the others care for her, that she's not alone. Fuku becomes inspired, and she powers up the Kamidake so it can move away from the pirates. Now, the Chobimaru can fire, but the pirates are terrified of both it and the even more powerful Ryo-Ohki that suddenly appeared. Their attempt to surrender is ignored and they get fired upon instead. The final scene shows Ryo-Ohki and the Chobimaru pursuing the sole-surviving pirate ship (presumably, the one housing Alan, Barry, and Cohen).
While Kiriko holds a sleeping Fuku in her arms, Seina speaks with Mikami and apologizes for making her worry, but Mikami tells him not to worry about it. Instead, as they're so close already, she tells him to take special leave to return to Earth and see his family, to which Seina agrees with delight from Amane, Kiriko, and Ryoko.
Trivia
- The Chobimaru and its "planetary obliteration weapon" is likely an homage to the Death Star from Star Wars.