In 1883 Koyo entered Daiichi High School; by that time, however, he was absorbed in writing poems under the penname of Enzan and after entering high school he participated in literary groups such as Bunyukai and Totsutostukai to deepen his interest in literature.
明治16年（1883年）に第一高等学校(旧制)に入るが、それ以前から緑山と号して詩作にふけり、入学後は文友会、凸々会に参加し文学への関心を深めた。