Middle-aged Koutarou Fujiki returns to his rural hometown with his wife Touko following the death of his father, intending to care for his aging mother. Shortly after their arrival, they learn that Tooru Kajiwara, Koutarou’s childhood best friend and rival for Touko’s affection, has recently died in an accident. The unresolved questions surrounding Tooru’s sudden disappearance from their lives decades ago resurface, haunting Koutarou. His unease deepens when he meets Kaoru, Tooru’s college-aged son, who has arrived next door to clear out his late father’s belongings. Kaoru is the spitting image of his father as a young man, and his presence resurrects the past in an unsettling yet compelling way.

The story moves between the present and the past, exploring the trio’s shared history. As teenagers and young adults, Koutarou, the quiet and introverted protagonist, and Tooru, the charismatic aspiring photographer, were inseparable neighbors whose friendship endured even after both fell in love with the same girl, Touko. The three formed a comfortable, if unusual, dynamic. But just as Koutarou and Touko’s relationship began to solidify, Tooru vanished without explanation. Now, twenty years later, Koutarou is plagued by two insecurities: why did his best friend leave, and would Touko have chosen him if Tooru had stayed?

As the summer unfolds, Koutarou, Touko, and Kaoru form an unexpected new triangle. For Kaoru, whose father was an enigmatic figure due to his career as a globe-trotting photographer, interacting with the couple offers a rare chance to understand the man he never truly knew. For Koutarou, facing Tooru’s look-alike son forces him to confront his long-buried guilt and regrets. The narrative uses the cleanup of Tooru’s house as a catalyst, with each discovered photograph and belonging prompting emotional flashbacks and difficult conversations about the past. Key arcs include a flashback to a pivotal aquarium date between Tooru and Touko, which provides a frank perspective on their feelings for Koutarou, and the gradual revelation of why Tooru chose to dismantle the triangle rather than watch it change.

The central theme revolves around the fear of change and the acceptance of loss. Tooru, who as a child cried over falling cherry blossoms because the flowers would die, is revealed to have run away to preserve his treasured memories of his friends, freezing their relationship in time. The arrival of Kaoru ultimately forces Koutarou to realize that life continued for Tooru after his departure, just as it did for him. The story concludes not with dramatic revelations, but with the quiet reassurances about love, friendship, and family that allow Koutarou, Touko, and Kaoru to finally move forward free from the ghosts of the past.