Masato Fukuroi, a college student and aspiring novelist, finds his studies often disrupted by romantic pursuits. He accepts a summer job at a hotel alongside his friend Yoshiro Oka. There, he reconnects with Chihiro Asaoka, a childhood friend from high school, and their relationship blossoms into romance and physical intimacy over the summer.

With the return of daily routines, Masato continues his studies while Chihiro works at a fast food restaurant. During autumn, he meets Rei Kashiwazaki and arranges an outing, coincidentally overlapping with a rock concert invitation from Chihiro. His attempt to juggle both fails, resulting in him having sex with Rei. This event triggers misunderstandings and a deterioration in his relationship with Chihiro.

Winter brings another brief sexual encounter for Masato, this time with a different woman, leaving him feeling increasingly unsettled and unfulfilled. This period clarifies his genuine emotional attachment lies solely with Chihiro. Introspection reveals his desire to reconcile and commit to her despite past complications.

Throughout these seasonal experiences, Masato interacts with other women: the tough Rie, the cute Miku Hayasaka, the energetic Chieri Sugita, and the faithful Kanna Yamabuki. These interactions contribute to his realization that spreading his attention leads to emotional dissatisfaction. His character development involves acknowledging his own mistakes in the relationship conflicts, including a willingness to forgive perceived indiscretions by Chihiro after recognizing his own faults. This maturity fuels his efforts to rebuild their relationship.

Masato's background as an aspiring novelist shapes his perspective on these experiences, though his literary ambitions remain secondary to his romantic journey. His arc concludes with a clearer understanding of commitment and emotional focus, moving from indecision to a dedicated pursuit of reconciliation with Chihiro.