Hashimoto Gaho studied Kano school painting with his father, Hashimoto Seien Osakuni, and later with Kano Shosen'in (1823-1880). He was a professor of Kano school painting at the Tokyo School of Fine Arts from its opening year of 1889 until 1898, and his famous pupils only increased his personal renown. Kawai Gyokudo (1873-1957), Hishida Shunso 1874-1911) and Yokoyama Taikan (1868-1958) were among his students.

Along with Kano Hogai (1828-1884), Hashimoto redirected and reinvigorated Kano school painting and together they founded the Kangakai (Painting Appreciation Society) in 1884. Hashimoto was honored by his appointment in 1890 as first court artist and in 1898 he co-founded another society with Okakura Tenshin (1862-1913) and their students called the Nihon Bijutsuin (Japan Art Institute, or Inten), an important artists' cultural group. He became a member of the Art Committee of the Imperial Household. Hashimoto is admired as a painter instrumental in the continued existence of Kano school painting. His landscapes are among his most accomplished works.