Arata Kaizaki, a jobless adult, undergoes an experiment that makes him 10 years younger. He goes back to high school and falls in love with Chizuru Hishiro, who is more than she seems.
| Actor | Role |
|---|---|
 Taishi NakagawaArata Kaizaki | Arata Kaizaki |
 Yuna TairaChizuru Hishiro | Chizuru Hishiro |
 Mahiro TakasugiKazuomi Oga | Kazuomi Oga |
 Elaiza IkedaRena Kariu | Rena Kariu |
 Sae OkazakiAn Onoya | An Onoya |
 Yudai ChibaRyo Yoake | Ryo Yoake |
 Mikako IchikawaMichiru Saeki | Michiru Saeki |
 Natsuna WatanabeAmatsu Kokoro | Amatsu Kokoro |
 Ayame MisakiHaruka Saeki | Haruka Saeki |
 Yuki KamedaTsukumi | Tsukumi |
 Mirai ItoStudent | Student |