(from ebookjapan): Keiko Egawa and Chiaki Tateishi were childhood friends, and in their hearts, they were in love with each other. However, Chiaki is about to give up on his love for Keiko due to a heart condition. Then, Yoshiko Hatanaka approaches Chiaki. One day, Keiko, who thought Chiaki hated her, receives a letter from Chiaki at her house saying he would be waiting for her at the park. ...... The story begins to move toward a shocking end.