Humans have created numerous universes, each one born of its creator's unique imagination. Souta Mizushino is a high school student who desires to be a writer and illustrator by creating and drawing his own light book. He is temporarily taken into a furious combat scenario while watching anime for inspiration one day. When he returns to the actual world, he discovers that something has gone wrong: the anime's headstrong heroine, Selesia Yupitilia, has somehow returned with him.