Kumiko Yamaguchi: 23 years old. A mathematics teacher at Akado Academy High School and the homeroom teacher of Class 3-D. Commonly known as "Yankumi." She hides the fact that she is the fourth-generation successor to the yakuza organization "Oedo Family" while working as a teacher.

Yamato Ogata Characteristics: Leader of one of the two major factions in 3-D. Appears rough at first glance but is a central figure who cares deeply for his comrades. Student

Ren Kazama Characteristics: Leader of the other faction opposing Yamato. Cool-headed and highly trusted by his peers. Student

Kengo Honjo Characteristics: A member of Yamato's close-knit group of friends. Student

Rikiya Ichimura Characteristics: A student with a stylish and flirtatious vibe who speaks with a regional drawl.

Satoru Kuraki Characteristics: Often seen with Rikiya; a compassionate mood-maker for the group.

Shunsuke Kamiya Characteristics: One of the classmates; this role marked the actor's debut.

Goro Sawatari: 45 years old. The Vice Principal of Akado Academy. He views the troublesome Class 3-D and Yankumi as enemies and is constantly in conflict with them.