The bathtub premise is not a setup for a plot; it's a declaration that nothing in Rito's life will ever make sense again. Every episode commits fully to the chaos of having a horny alien princess living in your house while your childhood friend circles like a shark and your little sister develops increasingly problematic feelings, all while the show treats this domestic nightmare with the straightest face possible. The comedy wins because it never apologizes for how absurd the premise is; it just keeps piling on until you're laughing at the sheer audacity of what passes for Rito's Tuesday. The actual romance between Rito and Lala sneaks up on you under all the panty shots and alien nonsense, which is where the show's real trick lives: it got you to care about two characters while you were too busy groaning at the perversion.

Rito Yuuki's life has not been quiet since Lala, an alien princess from the planet Deviluke, appeared in his bathtub and announced she would marry him. A year later she is trying harder than ever to win him over, even though she knows he loves his childhood crush Haruna, and Rito cannot help wondering how he really feels about her. Things get more crowded when Lala's younger twin sisters, Momo and Nana, come to Earth to meet her fiancé and end up living at Rito's house, alongside his dependable sister Mikan and Celine. Lala's inventions tend to go disastrously wrong, bounty hunters, body swaps and a sleepover gone badly add to the trouble, and Yami, a girl built as a living weapon, is under contract to kill him. Expect a comedic, ecchi sci-fi romance built on constant mishaps and awkward accidents, where simply surviving each day is an achievement for Rito.