In the aftermath of the most devastating conflict mankind had ever experienced, the tiny island of Shikotan became part of the Sakhalin Oblast... and on the unhealed border in this remote corner of the world, friendship among children from two different countries timidly blossomed, striving to overcome language barriers and the waves of history. Inspired by true events.
| Actor | Role |
|---|---|
 Masachika IchimuraTatsuo Senou (voice) | Tatsuo Senou (voice) |
 Yukie NakamaSawako (voice) | Sawako (voice) |
 Kanako YanagiharaMicchan (voice) | Micchan (voice) |
 Yusuke SantamariaHideo (voice) | Hideo (voice) |
 Kota YokoyamaJunpei Senou (voice) | Junpei Senou (voice) |
 Junya TaniaiKanta Senou (voice) | Kanta Senou (voice) |
 Saburo KitajimaGenzou Senou (voice) | Genzou Senou (voice) |
 Hiroshi InuzukaChief (voice) | Chief (voice) |
 Kaoru YachigusaOlder Sawako (voice) | Older Sawako (voice) |
 Tatsuya NakadaiOlder Junpei Senou (voice) | Older Junpei Senou (voice) |
 Polina IlyushenkoTanya (voice) | Tanya (voice) |