Born in Kurume City of Fukuoka Prefecture, SAKAMOTO studied oil paintings under MORI Miyoshi with AOKI Shigeru, his classmate, at junior high school in Kurume. When he was 18 years old, he worked as a substitute teacher of paintings in elementary school. In 1902, he met AOKI again, and intended to become a painter again. In the same year, SAKAMOTO was taken to Tokyo by AOKI, and entered the Fudosya, the atelier of KOYAMA Shotaro. He drew illustration in Tokyo Pack Company from 1908 to 1911, and was also active in Bun exhibition (Bun ten). In 1914, SAKAMOTO took part in foundation of the Nika Society (Nika-kai), and became a judge. In 1921, he went to Paris, and entered an academy at first, but left there in the next year. He studied freely while he tripped everywhere until he came back to Japan in 1923. After back in Kurume, he was active in the Nika exhibition (Nika-ten), and drew still lifes and landscapes from during the war to after the war. In 1956, he received the Order of Culture, and died in Yame City.
Sakamoto liked and painted horses so much that he came to be known as “a horse painter.” The period after he set up a studio in Yame town in Fukuoka Prefecture saw him concentrate particularly on paintings of horses grazing and plowing. He commented: “The figures of horses in vigorous motion perfectly suit Kyushu’s bright natural scenery, so rich in seasonal changes, and its relaxed climate. Horses have become an obsession for me.”