In 1885, with a group of friends, he formed the Kenyūsha, a magazine and literary association that exercised a major influence in the development of the Japanese novel for nearly 20 years. Through his study of Tokugawa period (1603–1867) literature, he led a revival of interest in the 17th-century writer Ihara Saikaku, whose sharp perceptions he blended with his own poetic aesthetic to create a style of romantic realism. Kōyō was active in the movement to create a new colloquial literary language. His elaborate style was well suited to love themes and descriptions of women. Early fictional works such as Ninin bikuni iro zange (1889; “Amorous Confessions of Two Nuns”) and Kyara makura (1890; “The Perfumed Pillow”) reflect his interest in 17th- and 18th-century literature. Later he displayed a more realistic tendency in Tajō takon (1896; “Tears and Regrets”) and Kokoro (1903; “The Heart”). His masterpiece was the novel Konjiki yasha (1897–1902; The Golden Demon), which portrayed the social cost of modernization when the power of money wins out over human affection and social responsibility. Kōyō's guidance was eagerly sought by young writers. Two of his best-known disciples were the romantic-short-story writer Izumi Kyōka and the naturalistic novelist Tokuda Shūsei.