Tsuruta Ichirou is known as the strongest kid and class. He had a reputation for being a bully due, it grew when he became friends with Kudoh. Its this that gets him suspended but eventually his suspension is lifted and he returns to school. His return and being quickly goaded into fighting sets an almost sorta turf war between the 3rd year students and the 2nd year ones. Its only until Kumiko intervenes, is Tsuruta able to be pulled out of fighting fully.
17 or 18
Tsuruta appears in chapter 31 (episode 9 in the anime). Tsuruta has a reputation for being the strongest in school and for knowing karate. He was suspended before Kumiko entered Shirokin staff. Before he was known as a bully and a friend to Kudoh. Though it seems Tsuruta was mostly goaded into fighting, Kudoh actually enjoyed it. All this fighting eventually got him kicked out, but Tsuruta was only suspended. And his days were almost over.
Something that is welcomed by the 3rd year students, not so much by the 2nd year ones; whom were bullied by Tsuruta and the third year ones. Tsuruta is shown being confronted by Ucchi, who wants to start a fight. Tsuruta is not so much interested, but changes his mind when his 3rd year classmen tell him that Ucchi made fun of his looks. Though he does kick Ucchi, Kumiko notices he held back his full strength.
Its the teacher, Hatta speaks out of concern, and tries to plead with him to not get into fighting. Its from watching these events, that make Kumiko question Tsuruta's perceived character. Though she has no time to explore it at the time. With Tsuruta back and often easy to goad, the 3rd year students chose this to gain their status back at the school. This constantly lead between fights with the 3rd and 2nd year students, both of which didn't want to back down. The fighting would often get so bad, that even the teachers drew a bit of a line in the sand, defending their students.
The 2nd year students decide to have a big fight out with the 3rd year students. And eventually set a trap for Tsuruta to even their score a little. Though silly, they literally did a bait and trap scenario. Tsuruta went to pick up a banana and fell in their dug out hole. Kumiko left both groups alone, figuring it's for the best the boys just fight out all the frustration. She got a ladder and helped Tsuruta out.
After a long talk, she came to an agreement. If she could beat Tsuruta in a fight, he'd have to listen to her, proving herself to be the stronger one. It didn't take a lot before she defeated him. Her conditions were for him to quit fighting and he had to focus more on his studies. Tsuruta was later shown joining Kumiko's class. Mostly because he realized he couldn't remember which grade he was.
- Tsurta appears in the anime version as well. Though his story is mushed in with chapter 10 and his from chapter 31-34. In the anime, he becomes part of the class's host club and shows a great love of cooking. But never really joins her class, though he does reappear in episode 11, to help the group when the boys attempt to free Shin from his father.
- Also in the anime its Minami who picks a fight with him. In the manga it was Uchi.