Kikuchi, a easygoing and somewhat dense high school student, enjoys spending time with his friend Seto at their homes after school. One day, after Kikuchi becomes interested in adult content, Seto proposes a way to assist him. This leads Kikuchi to discover new sensations through Seto's expertise, who happens to be gay. In a gesture of thanks, Kikuchi offers to reciprocate the favor. However, when Kikuchi notices Seto getting along well with a girl from their class, he experiences an unexpected pang of emotion in his chest.