Whilst Tenchi enjoys summer break with his friends in Tokyo, back in Okayama, Sasami is delighted when Yugi pays her a surprise visit. Whilst the two girls spend the day at the lake, Washu finally emerges from the lab with some interesting news- according to her research, Yugi originally came from planet Jurai! At Washu's request, Ayeka heads to the Okutama ruins, hoping that the ancient Juraian shrine will provide some clues as to who Yugi is, and how she came to end up on the Earth…
It is a hot summer's day, and as Sasami dozes in the sun, she finds herself once again dreaming of Yugi. As it turns out, she isn't the only one to be preoccupied with Yugi, as Ayeka soon discovers when Washu finally emerges from her lab. The genius scientist has been busy analysing Yugi ever since the girl came to the Masaki house, and according to her research, Yugi originally came from Jurai!
Naturally, Ayeka is curious as to how someone like Yugi could have originated on Jurai and then made her way to Earth. Washu is certain that the answers they need can be found in the old Juraian ruins Tenchi and his friends discovered in Okutama, and she asks Ayeka to go there and investigate. Deciding not to waste any time, Ayeka has Azaka and Kamidake fly her straight to the ruins.
Back at the Masaki house, Sasami and Ryo-Ohki are just about to return home from the lake when the forest around them suddenly falls silent. Looking around to see what has happened, Sasami is delighted to spot a familiar face- Yugi has come to pay her a visit.
Meanwhile, out in space, things are just as eventful, with Mihoshi and Kiyone having just been awarded medals for their part in helping to arrest Ryoko's henchmen. And their section chief has even better news for them- once Ryoko herself is arrested, the duo can expect a promotion back to GP HQ. It seems that Kiyone's dreams are about to come true, but instead of anticipating the future, she finds herself dwelling in the past- and the good times she enjoyed with Ryoko and the others before they all drifted apart.
Elsewhere, Ryoko is also remembering the good times she had on Earth, and begins to wonder if it wouldn't be a bad idea to go back there once in a while. Seeing her soften, Hotsuma is quick to turn Ryoko's thoughts back to the more painful memory of Tenchi and Sakuya, and just as he hoped, this quickly evaporates all her longings for her past life.
Whilst Yugi and Sasami play together by the lake, Ayeka finally makes it to the old ruins. Finding an old control panel, she has Azaka and Kamidake download what information they can, and play it back to her. As Ayeka reviews the old records, Yugi finds herself also recalling the events of long ago…
Three and half thousand years ago, during the reign of Jurai Empress Hinase, a six year old mutant began exhibiting strange and terrifying powers. That mutant was Yugi, a lonely little girl who desperately longed for some real friends. Using her powers, she summoned monstrous demons as playmates, terrifying the people of Jurai and causing untold damage. Finally, only the powers of the Jurai empress herself could stand against Yugi, banishing her demonic playmates, and sealing the frightened Yugi away in a sarcophagus. Hating what she had to do, but knowing it was necessary for the safety of her people, Empress Hinase banished Yugi, sending the shrine that contained her into the farthest reaches of space. For some reason, however, Yugi never made it to her desolate destination, instead landing on the Earth.
Being caught up in her memories naturally makes Yugi angry and miserable, but Sasami's cheerful optimism is soon able to cheer her up again. Meanwhile, Ayeka returns home and reports back to Washu, who begins to suspect that Yugi's awakening and the splitting up of Tenchi and the gang may not be unrelated. Worried that something bad may be about to happen, Washu reopens the dimensional tunnel (accidentally moving the terminus to Tenchi's toilet), and goes to pay Tenchi a visit.
Tenchi is busy planning the rest of his summer break with Sakuya, and when Washu appears out of the toilet and asks him to return to Okayama, he is less than willing to do so. Finally, Washu convinces him to return by telling him about Yugi's attack on the Masaki shrine, but when Tenchi agrees to go back, Sakuya immediately becomes upset, reminding Tenchi that he already promised that they would spend the vacation together.
As Tenchi tries to decide what to do, he is interrupted by another visit- this time from Umanosuke Tsuchida. Tsuchida's grandfather (Priest Tsuchida) has just been hurt in a traffic accident, and the Tsuchida family need Tenchi to fill in for him and conduct a traffic safety ceremony. Tenchi apologises as Tsuchida drags him out of the door, but a surprisingly calm Washu decides that Tenchi's presence back in Okayama probably isn't necessary just yet anyway. Instead, she heads back through the tunnel alone to get on with her research.
As evening draws in, Yugi asks Sasami to come home with her, suggesting that, as friends, the two of them should live together. When Sasami tells her that they are too young to do so, Yugi loses her temper, and flies off in a gust of wind. Left behind, Sasami can only wonder at what just happened to her friend, still unaware that what she knows about Yugi is far from the whole story…