Hiyoko, Kiiroi Ahiru ni Koi wo Suru

Ritsu Matsuoka is often distracted and absentminded. He finds a short love letter on his desk with no sender information and impulsively responds with a cheerful "I love you too." The two continue exchanging letters, making school more interesting. A friend’s remark makes Ritsu wonder if the messages are genuine. One day, returning to his classroom, he runs into Satsuki Hayato, a blonde student known for a tough, aggressive attitude. While Satsuki writes at the desk, he appears flustered. Ritsu suspects that Satsuki may be the anonymous letter writer.