Hikari Tsutsui, an otaku shut-in content with his anime figures and games, is assigned pool-cleaning duty alongside Iroha Igarashi, the school's most talked-about girl, known for skipping class and ignoring social norms. Despite their clashing worlds, Iroha defends Hikari against classmates who mock him, and the two begin dating. The catch: Iroha is set to transfer schools at the end of the year, putting a deadline on a relationship Hikari is only starting to understand.