Junko Omori lost her boyfriend, Kon Shiomi, in her third year of junior high school, and three years passed without her being able to recover from her grief. On the first day of her senior year of high school, a new student comes to visit Junko, but it is Kon's younger sister, Ai. Junko feels a trace of Kon and is filled with mixed feelings when Ai tells her that she entered the same school because of her admiration for Junko. The spirited Mai Okafuji depicts a supreme girl-meets-girl story that is both fragile and beautiful.