Yamaguchi, Kumiko

山口久美子

At 23, Kumiko Yamaguchi has finally realized her childhood dream of becoming a teacher. Unfortunately, the homeroom where she teaches math at Shirokin Gakuen Private Boys' High School is filled with juvenile delinquents (as is the rest of the school), led by the enigmatic Shin Sawada, forcing her to struggle to make them take their lessons seriously. If the students weren't difficult enough, the school's vice principal, Goro Sawatari, almost hopes Kumiko will fail at her job, occasionally sabotaging her efforts.
If everyone knew Kumiko's family history, they might be a little more careful around her. Kumiko is also the acting Koumichou, or head, of the Ooedo Clan, a powerful yakuza group. Her grandfather, Ryuichiro Kuroda, the Koumichou of the Ooedo and Kumiko's guardian since her parents' deaths, has fallen ill, so she must fill in for him. The group of hoods that often surrounds Kumiko (who they address as 'Ojou'), including Tetsu Asakura and Minoru Tatsuwaka, tend to be a bit overprotective of her. She has to assert her authority over these lunks to keep them in line... especially after they heard the students made fun of her on her first day in class!
Kumiko is an excellent martial artist, a skill that came in handy when she discovered that a former student of the school, Hiroki Kudoh, had sneaked back in to beat up the juniors, which included Kuma. However, Kumiko must be very careful not to let the secret that she is the Koumichou of the Ooedo slip. Shin suspects that there is something different about Kumiko, so she has to be careful around him.