Having lost his home planet to a society-ending war that he had started, the feline alien MuMu came to Earth to relearn technology. He then proceeds to crash his spaceship directly into university student Sakurako's apartment where he ends up staying. Amidst this abrupt new life together, MuMu immerses himself completely in researching home appliances - starting with the microwave!

Sakurako's apartment has become MuMu's new learning environment. His next topic to study: the paper-bag vacuum cleaner! Following the microwave and the refrigerator, Sakurako now finds her vacuum cleaner disassembled as well. Needing to try and repair it, she must ask the university's home appliance club, the "Mankind Regeneration Research Society"!

To better assist MuMu, Sakurako joins the university's home appliance club, the "Human Regeneration Study Group." Akihiro, the guy she secretly has a crush on, is also a member,. Is this her lucky chance to get closer to him? Meanwhile, MuMu finds himself cornered by his fellow alien compatriot, Decimaru. However, Decimaru has an unfortunate encounter with an automatic door...

The air conditioner in one of the culture club building's room broke down, and a new customer named Rakugo asks Sakurako and Akihiro to repair it. Although Sakurako is initially hesitant, she decides to take it up to move closer to Akihiro, who happens to also be clueless about home appliances, as they proceed with their investigation.