Having grown up enveloped in his mother's affection, Shota has lived with a deep regard for her feelings ever since losing his father at a young age. However, his emotions go beyond mere filial love—he harbors romantic feelings for her. One day, his mother, Hitomi, invites him on a trip just the two of them before he graduates from university, saying she wants to repay him for always being so consider ate and devoted. Her words stir Shota's heart, filling him with warmth and desire. At a hot spring inn, alone together, he slowly begins to reveal the secret emotions he has long kept hidden from her.