His real name was KOSUGI Kunitaro. In 1881, he was born in Nikko and initially studied western painting as an apprentice under IOKI Bunsai. However, he went to Tokyo and entered KOYAMA Shotaro's Fudosha Academy, changed his name to Misei became active in Taiheiyo Gakai(The Pacific Art Society) exhibition, and won several awards from the Ministry of Education sponsored exhibition.
During that time, he became acquainted with YOKOYAMA Taikan, and having had planned the "Free Painting Institute" initially enabled him to participate in The Japan Art Institute. KOSUGI Misei was also able to utilize the opportunity to participate in The Japan Art Institute when OKAKURA Tenshin passed away, and he began to supervise the western painting department then.
The Japan Art Institute's western painting department exhibition broke up after the seventh exhibition, and the artists dropping out of this institute formed a new art group called, "Shunyo-kai", and KOSUGI Misei also joined as a member. However, he gradually changed toward Nihon-ga(Japanese-style painting), and renewed his name to Hoan. In his later years, he lived in a mountain house in Akakura, Niigata-ken, and passed away in 1964 at the age of 82.
Some of his works include a wall painting in Yasuda auditorium of the Tokyo University, "Suigo(waterside village)", "Sandokiyu(mountain children playing)", and "Kintaro Yugyo(Kintaro)". These works appear to reflect his gentle look on nature which is said to contain his recollection of Nikko as an underlying theme. KOSUGI Hoan is an honorary citizen of Nikko.