Teppei is the uncle of Satoko and Satoshi who winded up adopting the two siblings following the deaths of their parents. Abusive of the siblings along with his wife Tamae, Teppei fled Hinamizawa after his wife's murder and settled in Okinomiya as a pimp who would blackmail and swindle people out of money with help from his new lover Rina. In Tatarigoroshi-hen and Minagoroshi-hen, Teppei returns to Hinamizawa forcing Satoko to live with him again and Keiichi and his friends try to figure out a means of freeing Satoko from her abusive uncle.