The soundtrack carries this show on its back, doing serious emotional labor that the harem premise has no business surviving. Comedy lands hardest when it stops trying to be cute and just lets absurdity run completely unchecked, pulling you away from the tired romance beats that would sink anything else. By episode six you realize the music isn't just accompaniment, it's the actual story the show is telling underneath all the fanservice.
Kazuto runs his family's public bathhouse with the kind of dedication most teenagers reserve for video games. His quiet routine shatters the night a UFO crashes into Earth, disgorging Walkyrie, a princess from deep space with an attitude to match her cosmic origins. When the accident literally binds them together through a shared soul fragment, Walkyrie finds herself stranded on this backwater planet. There's just one complication: the spiritual connection weakens her power, forcing her body and mind to regress into childhood. Now Kazuto has an alien princess living in his bathhouse who looks like a kid but still carries the arrogance of intergalactic royalty. Keeping her existence secret while running a business becomes impossible when she constantly causes chaos, blasts things with her powers, and refuses to acknowledge basic Earth etiquette. The show thrives on slapstick humor as Kazuto juggles his bathhouse duties, his new cosmic roommate, and the increasingly suspicious people around them. It's lighthearted comedy wrapped in sci-fi nonsense, where everyday life collides spectacularly with alien weirdness.