Manager of the Sotoba's doctor office and father to Tooru, Tamotsu and Aoi. Like his sons, Mutou has a very kind and gentle personality, as shown when the villagers all rose up against the shiki, saying he couldn't bear to drive a stake in his son's heart. He is also emotionally rational. He cares for his family very much, as well as the other villagers. He was the only one who reminded them that if their family members were killed by the shiki, there was also a possibility that those members rose up.
Using a PA system, he says that they're looking for a high school student and asks if he could ask them some questions. Tatsumi asks them to wait a moment and then opens the door. He says that nobody in the house has seen her but offers to help search for her, because the master of the house said that everyone should help one another. He says that his name is Tatsumi and he's a servant and asks how he can help. After hearing other villagers gossiping that they might have something to do with it, Mutou tells Tatsumi not to pay them any mind.