Daizen Tsutomu AKA Tetsuwan Tsutomu was a student from Suzuran All-Boys High School.
A former lieutenant of the Hana-Gumi, after his Boss Tsukishima Hana and the undefeated Hanaki Guriko graduated from Suzuran, Tsutomu is said to be without a doubt the school's strongest man. He also inherited Harumichi Bouya's Bullshit belt buckle from Hana. Making him the fifth owner.
He got his nickname due to his strong arm, much like cartoon character, Tetsuwan Atom. He lives up to this nickname through his signature move, the Bakudan Punch.
Despite his lack of fashion sense, Tetsuwan takes insults to his looks very seriously and is easily provoked by them. Most of the insults come from his friend and nemesis, Sawaguchi Masaru (a.k.a. Pudding). Tetsuwan and Pudding have a love-hate relationship, with the latter always provoking the former - which always results to Tetsuwan beating up Pudding later. But even if they are at each other's throats all the time, they are still each other's confidants and strongest allies.
Middle School Edit
Back in his middle school years, Tetsuwan had already built a fearsome reputation and maintained it by holding an undefeated track record.
He shares a rivalry with Tsukimoto Mitsunori from Housen which dates back to their middle school days. The two fought so much, that they each gave the other their scars after falling through a glass window while fighting in a mall .
His strength was so widely recognized, that by the time he entered Suzuran, only one person (his enemy-turned-ally, Nakamura Ginji) dared to fight him in his generation's Freshmen War. When he was a freshman, Tetsuwan already challenged both of Suzuran's strongest men (Hanaki Guriko and Tsukishima Hana) to separate fights, albeit loss both fights  , which put an end to his winning streak. His losses to the two made Tetsuwan Suzuran's third strongest man - a position he shared with Suzuran grad, Sakota Takefumi.
As a member of the Hana-Gumi, Tetsuwan has had his share of fights, the most notable of which is his one-on-one victory against Kagawa Kazuya (a.k.a. Gaga) of the Amachi Army . He also took part in the war against The Manji Empire. During Manji's assault on Suzuran, Tsutomu fought and defeated the Enomoto Group's leader, Hama Toshio .
During his senior year, Tsutomu along with Akaji and Aoji observe the final fight of the incoming generation's Freshmen War from Suzuran's rooftop. Tsutomu is seen smirking as Aoji notes that Suzuran's reputation must have spread overseas because of the foreigner Tyrone's presence at their school.
- Tsutomu vs. Aoji - Won 
- Tsutomu vs. Akaji - Won 
- Tsutomu vs. Ginji - Won, several times  
- Tsutomu, Akaji, Aoji, Pudding, Akutsu Kinji vs. Guriko - Lost 
- Tsutomu vs. Shinohara, two underlings - Won 
- Tsutomu vs. Mitsunori - Won 
- Tsutomu vs. Hana - Lost 
- Tsutomu vs. Gaga - Won 
- Tsutomu vs. Kaitou - Won 
- Tsutomu vs. Hama Toshio - Won