It spends twenty minutes being the dumbest fanservice comedy on the shelf and then quietly guts you, and it does that on purpose. The setup is pure nonsense: a space princess crashes into the family bathhouse Kazuto is barely keeping open, half her soul ends up in him, and she comes out the other side as a kid who can't be sent home without killing him. The gag work is genuinely unrestrained, the linework stays clean even when the show is at its silliest, and then the score walks in and starts treating the whole thing like it matters. That soundtrack is the reason people who should have dropped this in episode two are still defending it years later. Yes, the harem beats are stock and the romance is awkward by design. You'll still sit through the bath jokes for the ending.

Kazuto is working hard to keep his grandfather's public bathhouse going when a princess from outer space crashes onto Earth by accident. Through a turn of events, Kazuto ends up holding part of Princess Walkyrie's soul, and that bond means she has to stay with him. Her troubles do not stop there: with her soul weakened, the princess shrinks into a small child in both body and mind. The result is a sci-fi comedy with an ecchi streak.