Out in the depths of space, the infamous scientist Dr Clay decides that it is time to pay a visit to his mistress, the powerful lady Tokimi. Taking his robotic servant Zero with him, Clay leaves his spaceship, and heads out for an audience with Tokimi.
Before he can see Tokimi, Clay must first talk to her subordinate D3. D3 reminds Clay that he has yet to complete the last mission that he was assigned, but Clay is certain that he has something far more interesting to offer- the whereabouts of a certain person that Tokimi is rumoured to be searching for.
Her interest piqued, Tokimi agrees to an audience with Clay, and the high-level dimensional being materialises before him. As Tokimi already knows, the person Clay has found is none other than Washu, and she gives him clearance to capture the genius scientist- as long as he remembers to bring her to Tokimi alive. In return, she will grant him dominance over one entire galaxy.
Back on Earth, Sasami and Mihoshi are busy cooking dinner, whilst Ryoko has gone out to buy some sake. On the way home, Zero intercepts Ryoko, and surrounds her with tentacles of orange goo that merge together and immobilise her. As Ryoko struggles to escape, Zero uses her special abilities to duplicate Ryoko’s form, abilities and memories. The only thing that cannot be duplicated is the gem on Ryoko’s left wrist, so Zero is forced to take the original gem before sending the real Ryoko up to Dr Clay for him to analyse.
Meanwhile, back in her lab, Washu is busy studying Tenchi in the hopes of finding out how he generated the Light Hawk wings in his battle against Kagato. Tenchi has been unable to duplicate that feat, and Washu theorises that they only appear when needed. However, any further analysis will have to wait until later- dinner is ready.
Ryoko still hasn’t returned home, so whilst the others wait impatiently for her to arrive, Tenchi decides to go out and look for her. Meanwhile, Zero sneaks up to the Masaki house, and seeing a seemingly defenceless Washu relaxing in front of the television, decides to capture her straightaway. Unfortunately for Zero, Tenchi catches sight of her. Believing her to be Ryoko, Tenchi calls to her to come in for dinner- but when Zero turns to reply, she freezes and turns red as she is suddenly hit with the full force of the real Ryoko’s feelings for Tenchi. Overwhelmed by Ryoko’s feelings, Zero starts flirting with Tenchi, at least until Ayeka interrupts them. Tenchi quickly goes in for dinner, but Zero remains outside, restless and confused over these new emotions.
After dinner, Washu decides to gather life form data on the others as part of her research. After finishing with Ayeka, Washu decides to move onto ‘Ryoko’. Zero reluctantly agrees, but soon becomes worried when Washu’s tests seem to reveal that something is amiss. As it turns out, Washu has discovered something important- Zero/Ryoko’s breasts are sagging!
That night, Clay reminds Zero of her mission, and by the next morning, Zero is ready to get back to the business of capturing Washu. Whilst Washu stands outside watching Tenchi run to the fields to escape her tests, Zero jumps down to capture her from behind, but becomes frozen when she sees that Tenchi has returned to get his gloves. Speechless and red as Ryoko’s feelings resurge, Zero is once again unable to move. Dismissing the motionless ‘Ryoko’ that has suddenly appeared behind her, Washu goes back inside, evading capture once again.
Later, Zero decides it is time to have another go at capturing Washu, this time by sneaking into the lab. Once again, however, she is interrupted by Tenchi, and Zero is soon fighting off Ryoko’s feelings as he reminds her to get started on the laundry.
Whilst Mihoshi heads off in her ship to investigate an interstellar robbery, Zero finally manages to make it into Washu’s lab, but as before, no sooner has she snuck up behind the genius scientist than Tenchi arrives, this time to announce that dinner is ready. Caught once more, Zero quickly pretends that she just came to the lab to help Washu, which only succeeds in landing her with some of Washu’s donkey-work.
Zero is quickly becoming distracted by all of these new and unexpected feelings. Drawn to the old shrine by Ryoko’s memories, Zero spends some time there thinking of Tenchi. When she finally returns home, the perfect opportunity to complete her mission presents itself when Washu suggests that they take a bath together.
After scrubbing herself, Washu tells Zero/Ryoko to come over so that her ‘mother’ can scrub her- after all, she needs to be nice and clean for Tenchi! Distracted by thoughts of Tenchi, Zero complies. As she washes her ‘daughter’, Washu is quick to spot something- unlike Ryoko, Zero has Dr Clay’s logo on her bottom. Seeing this, the mischievous scientist cannot resist tricking Zero into cleaning the toilet by telling her that Tenchi was wondering why Ryoko hadn’t done it yet. When Zero quickly rushes to scrub the toilet, Tenchi is amazed that she would volunteer for such a task- especially when it was Washu’s turn to do it.
Despite falling for Washu’s ploy, Zero is not unhappy- after all, she did manage to impress Tenchi. Dr. Clay, however, is far from impressed- Zero still has her mission to accomplish, and it looks like Tenchi is proving to be an obstacle to their goals. Imparting one last order to Zero, Clay terminates their conversation, and Zero returns to Earth.
That night, Zero sits alone in the darkness, consoling herself with a cup of sake and her memories of Tenchi. For, first and foremost, she is a loyal servant of Dr. Clay, and now she must obey the orders he gave her. Teleporting into Tenchi’s room, Zero recalls Clay’s words- if Tenchi is in her way, then he must be eliminated. And now, as Tenchi sleeps peacefully in his bed, he is defenceless as Zero uses Ryoko’s powers to create a short energy sword, which she brings stabbing down towards him…