Ryotaro is a boy who loves robots and lives out in the country with his three sisters, but he's headed to Tokyo for high school. Before leaving, he runs across a humanoid military robot and has a fateful encounter with its pilot, a cute teenage girl who calls herself La Vie en Rose. Ryotaro will almost certainly meet her again in Tokyo, considering his family connection to the production of these humanoid robots--his father worked with them.

A boy falls in love with a girl, who he witnesses urinating in public.

Unable to confess, he is gifted with by a deus ex machina with the girl's sudden transfer to his school. Never minding the coincidence, he immediately calls out to her, and is overjoyed to find out that she wet her pants the moment she saw him.

Hijinks ensue as the two strike up a deal to partake in their darkest, most wild urine-based fetishes. While the two engage in watersports, DRAMA ensues as they begin to fall in love with each other instead and question the NATURE of PISS.