Shinjirou was a member of the Muhou School and member of Maniwa's second raid squad.
Shinjirou is a young man with short spiky hair of a light color (possibly red) and prone to grinning. He wears a shirt adorned with black stripes and the Muhou School symbol, baggy pants and bandages on the shins. He wears a chainmail under his shirt. When not fighting, he carries his nunchaku around his neck.
Shinjirou is cocky, hot blooded and overconfident. However, he becomes cowardly after witnessing Iori Sengoku in battle and is afraid at the idea of facing him again. He also finds Ippi's habits disgusting.
At some point he joined the Muhou School and was put into the Second Raid Squad, under Maniwa's command. They were given the task of witnessing the battle between the Ogame School and the Myoujin School and try to hire the winners.
Myoujin School ArcEdit
Shinjirou appears in the ceiling of the Jouchi School dojo, waiting for the conclusion of the battle between the Ogame School and the Myoujin School. As Naokatsu is killed, he jumps in the fray along with his companions. He, Chuuji and Tagosaku takes on Iori, as he gives out the most dangerous aura of the trio.
Muhou Invasion ArcEdit
After Yamashita's failed assault, Shinjirou grins and tries to hit Iori with his best attack, Saishigeki, but Iori dodges, gives him a four and nearly cleaves him in half. Saved by his chainmail but yet wounded, Shinjirou is saved at the last second by Chuuji. When Chuuji ensnares Iori with his chains, Shinjirou's takes one and tries to suffocate Iori, but to no avail. When Maniwa is killed, he and the others retreat.
Iori Invasion ArcEdit
He's later seen in Unabara Castle, witnessing Iori's attack. He discuss a tactic with Soun and Ippi, however he's scared at the tought of facing Iori again. When Iori manages to get through the ambush and kills Chuuji and Soun he decides to flee. However, he and Ippi are captured by Nachi and send back to Jinsuke, where we find out that he was beaten with his own nunchaku to the point that his face is unrecognizable. However, he hasn't been confirmed dead by the author.
Shinjirou is stronger than the average warrior, but not powerful enough to compete against stronger enemies. He fights with a nunchaku, a weapon that, according to Iori, is difficult to defend against due to the unpredictable movements of the chain.
Shinjirou's Unnamed Nunchaku: Shinjirou carries a nunchaku with him, usually dangling from his neck. The sticks of the nunchaku are black and covered by a spiral pattern, similar to those of Tagosaku's staff.
Saishigeki (Fiery Strike): Shinjirou holds the nunchaku with Battboth hands, with one stick over his shoulder and the other one under his armpit, and pulls them both with great strength in order to build up the energy. Then, he suddenly let the inferior stick go, resulting in a very powerful overhead slam.