The Age Gap Sister is at That AgeSou iu Toshigoro ni Nacchatta Toshi no Sa Shimai; Age Gap Sisters Who Have Reached That Age; The Age Gap Sister is at That Age; そういう年頃になっちゃった年の差姉妹

Two sisters, with ten years separating them. Once close, they grew distant with time. As the younger sister enters high school, their relationship once again begins to change. This time in an unusual direction.