"Izumi Ako" and "Izumi Komachi" are twin sisters. They have been in tune with each other since childhood, but as they entered their third year of high school, Ako began to feel a vague sense of discomfort and anxiety. Seeking a source of emotional support other than Komachi, Ako forcefully approaches her homeroom teacher, "Osawa Maki," in the classroom after school and kisses her. However, her sister Komachi sees this from the opposite building... A twisted sisterly love. A juvenile story that rekindles their bond at the end of youth.