Due to illness, Nagai spent several months in 1895 in a hospital in Odawara. From 1897 on, he started his regular visits to the Yoshiwara red-light district, accompanied by his friend and writer Seiichi Inoue (1878–1923). The same year, he graduated from Junior High School. With his mother and younger brothers, he visited Shanghai, where his father was working for Nippon Yusen. He returned to Japan in Autumn and enrolled in the Tokyo School of Foreign Languages.
