Mori Kansai was born in Hagi, the conservative Chōchu stronghold (Yamaguchi pref.) as Ishida Kōshuku. After training with a local artist, and a period in Edo, he moved to Osaka in 1831 to study with Mori Tetsuzan, who adopted him when he married his daughter in 1838. Subsequently Tetsuzan sent him to Kyoto where he was successful as a professional artist in the Maruyama school. In the 60s he got involved in the political activism of the Sonnō Jōi Movement. After the Meiji restoration this added to his reputation and prominent position as an artist-statesman. Mori Kansai was a distinguished representative of the Maruyama school, but he did not take part in its modernisation. He led a literati lifestyle, presiding over the activities of the Joun-sha Kyoto painting circle after the death of Shiokawa Bunrin in 1877. He studied Nanga style painting all his life, which shows most clearly in his later work. Kansai was master in a variety of techniques, including ink painting. He is said to have painted directly without any preliminary sketches. His best known pupils are Yamamoto Shunkyo and his adopted son Mori Yūzan. In 1893, celebrating his 80th birthday an exhibition of more than 600 of his works was held in Kyoto. Yet now not many of his works are known. He died in 1894.