Itsuki Hashima, a light novelist, has an intense fixation on little sisters, a theme he deliberately weaves into his stories. Despite his peculiar obsession, he enjoys the support of a tight circle of friends: Nayuta Kani, a brilliant yet lecherous novelist who harbors romantic feelings for Itsuki; Haruto Fuwa, a fellow male writer who has found considerable acclaim; Miyako Shirakawa, a friend from college; and Chihiro, his perfect younger stepbrother who manages the cooking and housework. The group passes the time by engaging in bizarre games, taking spontaneous trips, exchanging jokes, and commemorating their successes. Yet they also confront personal struggles, from racing against tight deadlines to grappling with painful memories from their past.