The main protagonist of Hyouka, he is a rational boy who lives by "If I don`t have to do something, I won`t, but if I have to, I`ll do it quickly." He only joins the Classic Literature Club at the request of his older sister, Oreki Tomoe, to stop it from being dissolved. He says that he doesn`t like to waste energy, but if given a mystery to consider, he will see it through until it is solved with his brilliantly logical deductions. To him, Eru is "someone he can`t ignore," hinting that he may have feelings for her. At her urging, he soon finds himself more involved with high school life.