Shiba is extremely durable and has very powerful will. He participated in the Maximum Tournament. Shiba have an incredibly tough skull and often uses a headbutts. When Iron Michael, a powerful champion boxer, punched his forehead, he finished with a broken arm. Once he was hit by a motorbike and survived.
He is a street fighter that doesn't seem to feel pain. It is unknown whether Shiba trained any form of combat, probably he just uses his brute force. In the fight with Kohei Hatanaka, Shiba managed to break his own left arm to intimidate his opponent, then Chiharu started to beat him mercilessly. Shiba also uses dirty tactics sometimes.