A high school girl, Sayaka Kudō was the bottom of the class. After a year, she improved her deviation value from 30 to 70, then passed Keio University that is considered one of the most difficult to enter in Japan.
| Actor | Role |
|---|---|
 Kasumi ArimuraSayaka Kudo | Sayaka Kudo |
 Atsushi ItoYoshitaka Tsubota | Yoshitaka Tsubota |
 Shuhei NomuraReiji Mori | Reiji Mori |
 Yoh YoshidaAkari Kudo | Akari Kudo |
 Tetsushi TanakaToru Kudo | Toru Kudo |
 Ken YasudaTakashi Nishimura | Takashi Nishimura |
 Morio AgataMakoto Minegishi | Makoto Minegishi |
 Airi MatsuiMika Honda | Mika Honda |
 Yuhei OuchidaRyuta Kudo | Ryuta Kudo |
 Kokoro OkudaMayumi Kudo | Mayumi Kudo |
 Nanami AbeYui Okazaki | Yui Okazaki |
 Rie MinemuraReiji's Mother | Reiji's Mother |
 Maharu NemotoChild Sayaka Kudo | Child Sayaka Kudo |
 Ruka WakabayashiYoung Ryuta Kudo | Young Ryuta Kudo |
 Rinko KawakamiYoung Mayumi Kudo | Young Mayumi Kudo |
| MMochika YamadaYoung Sayaka Kudo | Young Sayaka Kudo |
 Kenichi YajimaHigh School Principal | High School Principal |
 Yasuhi NakamuraElementary School Teacher | Elementary School Teacher |
 Aoi ShimoyamaJunior High School Student | Junior High School Student |