He began his career under his surname Iwasaki. He made his debut in the
jonokuchi division at
Nagoya in July 2012 and won all seven of his contests to win the division and ensure immediate promotion to
jonidan. He faced fellow 7–0
stablemate Hamaguchi in a playoff for the
championship; the only situation in which stablemates are allowed to face one another. In September he recorded another perfect record in the
jonidan division. Notably, he again faced stablemate Hamaguchi in a playoff, which he again won. This was the first time in sumo history that two stablemates had faced each other in a championship playoff in two consecutive tournaments. In November at
Fukuoka he secured a third consecutive promotion when he recorded a 6–1 record in the
sandanme division. For the next eleven tournaments, Iwasaki competed in the
makushita recording more wins than losses
(kachi-koshi) on all but two occasions. and adopted the ring name
(shikona) Hidenoumi. In his first appearance in the division he recorded seven wins and five losses, but missed three bouts through injury. After recording winning records in the next three tournaments he was promoted to the top
makuuchi division for the
Nagoya tournament in July 2015. and the first since
Chiyomaru and
Chiyoōtori in March 2014. He produced his first winning record in the top division at the seventh attempt, a 10–5, which saw him promoted to his highest rank to date of
maegashira 6 for the May 2021 tournament. He remained in the maegashira ranks for the rest of 2021.
Illegal gambling probe On 22 December 2021, Hidenoumi and his stablemate were withdrawn by their stablemaster Kise Oyakata (former
maegashira Higonoumi) from the January 2022 tournament for suspected involvement in
illegal gambling. Both were interviewed by the
Saitama Prefectural Police on 7 January 2022. According to investigators, the illegal gambling operation ran out of a store in
Sōka. Employees and customers of the establishment were arrested on suspicion of illegal gambling when it was
raided in September 2021. During the investigation suspicions were raised about the involvement of both Hidenoumi and Shiden, as well as other sumo wrestlers that may have possibly visited the establishment. It was later reported that prosecutors would likely not file charges against the two wrestlers. On 15 January 2022, Japanese media outlets reported that the Sumo Association's compliance committee, after holding hearings, concluded that Hidenoumi and Shiden participated in illegal gambling. The committee found that Hidenoumi and Shiden visited the establishment on two occasions in July and August of 2021 during the time that the Sumo Association had relaxed
COVID-related restrictions on going out. They both played an illegal slot machine, with a stake of less than 100,000 yen. The findings were reported to chairman
Hakkaku on 13 January, and the full board of directors was expected to take up the matter during their regular meeting on 27 January. The committee's report recommended a suspension of one tournament for Hidenoumi and no suspension for Shiden. Three days later, Hidenoumi was ranked back in the
jūryō division on the March 2022
banzuke. He remained in
jūryō until September 2023, when he was demoted out of
sekitori status for the first time in nine years. After winning five of his seven bouts in
makushita, the Sumo Association announced that he would return to
jūryō for the November 2023 tournament.
Retirement Hidenoumi eventually returned to the
top division for the July 2025 tournament, but withdrew after going winless in his first four matches. His stablemaster Kise told reporters that Hidenoumi injured his right calf in his Day 4 contest against
Kotoeihō, and that he was expected to re-enter the tournament once the pain went away. He lost to
Kusano in his return match on Day 8. Hidenoumi then recorded three consecutive in the division, with ten losses from the bottom of the division in January seeing him relegated to for the first time since September 2023. Hidenoumi finished the March 2026 tournament with a 3-4 record, losing on the final day to . He announced his retirement following the conclusion of the tournament. ==Family==