- VOICE RANGE: MEDIUM  - 

Teppei is Satoko and Satoshi's uncle. He and his wife Tamae were forced to take care of them after the death of their parents, but they abused them, forcing them to do strenuous tasks for him, or enduring near impossible situations as punishment while he lazes around the house drinking, playing games or watching TV. After Satoshi kills Tamae and runs away, he takes his anger out on Satoko, leaving her in a fragile mental state where she hopes that if she endures the abuse, Satoshi might come back. Teppei currently lives in Okinomiya. According to Kasai, he is a procurer and uses his lover Rina to swindle men out of their money. In the third arc, he is killed by Keichi. as an attempt to protect Satoko, and by Rena in another arc when he and Rina try to blackmail her father. Shion also contemplates killing him in a later arc to protect Satoko, but is stopped by Keiichi before she can make the same mistake. However, in a different arc, Keiichi doesn't stop Shion, instead teaming up with her and Rena to kill Teppei.