Nanami Ishikawa works as an editor at a publishing company. She travels Hiroshima to go after her father Asahi who left home. During her visit to Hiroshima, she learns about the tragic story of Asahi's older sister Minami Hirano. When Minami Hirano was 13 years old, she was exposed to radiation by an atomic bomb.
| Actor | Role |
|---|---|
 Takako TokiwaNanami Ishikawa | Nanami Ishikawa |
 Isao HashizumeAkira Ishikawa | Akira Ishikawa |
 Yuna TairaFuko Ishikawa | Fuko Ishikawa |
 Rina KawaeiMinami Hirano | Minami Hirano |
 Midoriko KimuraFujimi Hirano | Fujimi Hirano |
 Asuka KudoAkira Uchikoshi | Akira Uchikoshi |
 Fuka KoshibaKyoka Ota | Kyoka Ota |
 Yōsuke AsariAkira Ishikawa (Young) | Akira Ishikawa (Young) |
 Shosuke TaniharaNot listed | Not listed |
 Shuji KashiwabaraNot listed | Not listed |
 Mitsuo SagawaAkira Uchikoshi (Old) | Akira Uchikoshi (Old) |