All his life, Manamichi has only known how to study. When summer break arrives, his simple routine is disrupted when he is tasked with delivering homework to his classmate, Makura Koiro. Upon visiting her home, he discovers that Makura spends all day lounging in her pajamas, relaxed and with her guard down. Seemingly unbothered by his presence, she makes him a simple but unexpected proposal: “Hey… wanna slack off together?”

This marks the beginning of an unconventional summer for the studious boy. The story follows Manamichi and Makura as they spend their days playing video games, sharing meals, and indulging in the quiet joys of doing nothing productive. The setting is primarily Makura’s room, a private space where normal social rules are suspended, and the pajamas she wears become a symbol of her vulnerability and the intimate, carefree atmosphere between them. As time passes, their physical and emotional closeness deepens, leading to moments where they unexpectedly end up sharing a bed.

Manamichi is characterized by his rigid, study-focused past and his gradual awakening to the value of relaxation and companionship. Makura Koiro presents a stark contrast; while she appears listless and lazy, her invitation to slack off is an active choice to connect with someone outside the pressures of school. The supporting framework includes the original source material by author Kizu Kanoda and character designer Yukiko Tadano.

The narrative is structured as a feel-good romantic comedy that prioritizes emotional warmth and small, everyday routines over dramatic conflicts. It explores how two people lower their defenses and build a relationship simply by existing comfortably in the same space. The manga adaptation was confirmed to conclude with the release of its third compiled volume, bringing this cozy story of summer companionship to a close.