Born Kumiaki Sawaka, he joined Dewanoumi stable in 1935 and initially fought under the shikona of Hamanishiki, before changing to Masuiyama in 1937.

In the first postwar tournament held in a bomb-damaged Kokugikan in June 1945 he could manage only two wins and dropped back to the maegashira ranks, but he was runner-up to Haguroyama in November 1946 with a fine 11–2 record (alongside his stablemate Shionoumi).

After earning his first sanshō or special prize for Technique he returned to the san'yaku ranks, and in October 1948 he won his first top division championship.

In his second tournament at ōzeki rank Masuiyama took his second and final championship, defeating yokozuna Haguroyama, Azumafuji and Maedayama on three consecutive days to finish 13–2.

In November 1984 Masuiyama reached the mandatory retirement age set by the Japan Sumo Association and passed on control of Mihogaseki stable to his son.