Sakurako Umeyashiki, a university student originally from northern Japan, lives alone in her Machida apartment on Tokyo's far western edge. Her ordinary student life shatters when the extraterrestrial MuuMuu crash-lands directly into her home. This sudden arrival forces an unplanned cohabitation, disrupting Sakurako's established routines.

Sakurako struggles with pronounced social anxiety that shapes her daily interactions and personal engagements. Despite deep initial reservations about her alien housemate, she gradually takes on the role of explaining terrestrial technology to the curious MuuMuu. She often scours the internet for appliance mechanics to bridge her own gaps in understanding, conveying complex concepts without full technical comprehension. This positions her as a unique intermediary between human innovation and extraterrestrial inquiry.

Her daily existence now revolves around managing household chaos caused by MuuMuu's relentless experimentation, which frequently involves disassembling devices like microwaves and refrigerators. These incidents demand constant repairs and replacements. Concurrently, within her academic world, Sakurako navigates social complexities, including a tentative connection with classmate Akihiro Tsurumi, who displays a notable affinity for cats. This human relationship unfolds alongside her extraordinary extraterrestrial living situation.