During summer break, Manamichi, who had been spending his days buried in studies, was tasked with tutoring his classmate, Makura Koiro. When he visited her apartment, where she lived alone, she greeted him in her pajamas and surprised him with an unexpected proposal.

"Hey... let's just indulge together, okay?"

Spending time with Koiro, who remained in her cute pajamas and was full of vulnerabilities, they played games, ate meals, and before he knew it, they were sleeping side by side...