Ochiai, who is gloomy and shy, wasn't good with his kouhai who is cheerful and has high communication skills in contrast to himself, Kirigaya. Kirigaya died suddenly in an accident a year ago. Ochiai continues to regret having hit Kirigaya with frustration just before he died. One day, a ghost of Kirigaya appears in front of him... The bay of the tranquillity night. The exchange between the two lonely people begins.