The dean of the hospital in Sotoba, Toshio resigned from university hospital, returning to take up his father's position when he passed away. He is fondly given a nickname, "Waka-sensei", by his colleagues as well as the residents. Toshio has a dislike to both his mother and his late father, as both of them often put reputation of the Ozaki family before anything else. He is childhood friends with Seishin Muroi and Mikiyasu Yasumori. Toshio is a chain smoker and is married to Kyouko who manages an antique shop. He is baffled by the mysterious deaths and swears to solve the case and protect his village. One of the two main protagonists in the series.

Spoiler

Although he later discovers the truth behind the villagers' death, Toshio is still unable to do anything, as the villagers around him refuse to believe his words and Toshio cannot single-handedly go against Tatsumi, or the roaming Shikis. Still, he vows to put an end to the Shiki's massacres, and secretly teams up with Natsuno, who has become a werewolf like Tatsumi. He lets himself get bitten by Kirishiki Chizuru to lure her out to the village's festival and kill her there, effectively exposing the truth about the Shikis to the village. Afterwards, he leads the villagers on a brutal Shiki extermination, which only ends when the village is burned down.