Mutou Renji was a student from Suzuran and resident of Room 1.
Renji is considered a rarity at a place like Suzuran, since he is the perfect combination of brains and brawn. His balance of smarts and strength has earned him the nickname Mad Dog.
Like Sakota, Renji voluntarily bowed out of his generation's Freshmen War after witnessing Tsukishima Hana beat Sakota in a one-on-one. After Hana's victory in the War, Renji decided to follow and promote Hana as Suzuran's future leader. He, together with Sakota and other handpicked freshmen, formed the Hana-Gumi. Today, Renji is the second in command of the Hana-Gumi.
As the group's lead tactician, Renji rarely participates in fights, often preferring to gather intel and form battle plans from the shadows. He also serves as the group's voice of reason and never hesitates to give Hana counsel when he needs it. His opinion is highly-valued within the members of the Hana-Gumi and without him, the group would crumble.
On the evening of the Hana-Gumi's war against the Amachi Army, he challenged Hana to a fight to prove to himself just what kind of a man he really was. Renji lost that fight , but ended up teaching Hana a few more important lessons.
Renji also involved in the war against The Manji Empire.
After graduation he's planing on moving to Tokyo.