Murakawa Katsuhiro is one of the original members of the Hana-Gumi .
He first encountered Hana as an opponent in the Freshmen War. He was easily defeated by Tsukishima Hana, and promptly changed his hairstyle into a mohawk.
Initially a follower of Hana and the others against their wills, he became a valued member of the faction and lived up to his position as officer, becoming close with the other members due to his optimism and strength.
Although he was first seen being defeated by a single punch by Hana , he progressively became stronger throughout the series, providing the Hana-Gumi with both added muscle and respect due to his reputation in middle school.
- Murakawa vs. Hana - Lost 
- Murakawa, Fujishiro, Yaita, Ozaki, Zenjirou, Sakota vs. Team Tahara - Won