MuMu, who once destroyed his home planet by triggering a war, comes to Earth to relearn technology. He crashes his spaceship into Sakurako’s apartment and ends up living with her. He becomes obsessed with Earth appliances, especially the microwave.
Mumu continues to attack Sakurako's appliances, still devastated by the loss of her microwave and refrigerator. Unsure of what to do, she finds herself seeking help from her university's cultural associations.
The Keikyu University festival is in full swing, and while Sakurako initially enjoys the atmosphere that permeates the campus, Tenkûbashi has a little surprise in store for her.
Sakurako is engrossed in an AR cat collecting game. When she heads to the park where a strong opponent is said to appear, she finds the familiar characters gathered there? Meanwhile, Sakurako becomes suspicious of Moomoo, who keeps going out at night. She secretly attaches an action camera to him, and what she sees on camera is...
Sakurako and Muumuu carry their neighbor Kitashinagawa, who has passed out drunk in the park, back to her room. After seeing her room, Sakurako notices something and decides to lease a refrigerator from the Human Regeneration Research Society. But behind the scenes, Carnival, the most heroic radical, is also eyeing the refrigerator?
Rokugo represents the club in their regular outdoor volunteer activities. Worried about the gazes of the girls, including Akina, he decides to get in shape using an EMS muscle training machine. Meanwhile, Sakurako is troubled by the rising cost of utilities. She tries various ways to save money, but...
The members of the Human Regeneration Research Society and Sonoko are volunteering at a nursery school. They have a hard time dealing with the children every day, so they decide to plan a strategy for their next play. Meanwhile, the Human Regeneration Research Society is in the midst of a big end-of-year cleaning. Then, a mysterious videotape is discovered.
Decimal is troubled by Akihiro's fixed gaze. It seems he is worried that he doesn't use the cat litter box, but as cat-like aliens have no concept of excretion, he doesn't really understand. While Sakurako is explaining how the litter box works, he bumps into Samezu?
Tenkubashi and Sonoko have a secret routine, but Sonoko rejects him, telling him to "stay away from me." However, will this be the catalyst for a change in their relationship? Furthermore, Sakurako and Akihiro also see progress through a demonstration sale of disaster prevention goods.
A retro boom is sweeping the nation among young people. Sakurako and Tenkubashi compete to see who has the best taste in retro home appliances stored in the Human Regeneration Research Society's warehouse. On their way home, Muumuu tells Sakurako that he envies the culture of looking back. Behind this lies the words of a certain researcher...
Appearing before the Moomoos are the remains of the Brain, who once controlled the war - a clone of Doctor Octal, created as a way to spite the Moomoos. Meanwhile, Sakurako and Anamori are being held captive along with Samezu. How will they overcome this crisis?
The Earth is on the brink of destruction due to the aftermath of a conflict between extraterrestrial life forms. In this desperate situation, Tenkubashi says, "There is a way to save the Earth!" That way is to stop the Earth. In order to overcome this unprecedented crisis, will the feelings of Earthlings be united through "cats" and smartphones?
