is a Japanese professional sumo wrestler or rikishi from Elhovo, Bulgaria. He made his professional debut in 2009, reaching the top division two years later, debuting in the November 2011 tournament. Aoiyama has won four Fighting Spirit awards, one Technique award and one kinboshi for defeating a yokozuna. He has twice been runner-up in a tournament. His highest rank has been sekiwake. Aoiyama is one of the heaviest competitors in sumo, weighing around 200 kg for most tournaments. In March 2022, he obtained Japanese citizenship.
Early life and sumo background
After wrestling for ten years and doing amateur sumo for three, he entered the professional sumo world at the introduction of fellow countryman, ōzeki Kotoōshū, becoming only the second Bulgarian rikishi. He joined Tagonoura stable, run by former maegashira Kushimaumi. When asked by his coach whether he preferred mountains or rivers, he chose mountains and so was given the shikona of Aoiyama, meaning "blue mountain".
Career
Early career
In his professional debut as Aoiyama Kiyohito in the September 2009 tournament, he won the jonokuchi championship with a perfect 7–0 record. He subsequently changed his name to Aoiyama Kōsuke for his jonidan debut in the following November tournament, which he also won with a 7–0 record followed by a playoff win against the sole Kazakhstani wrestler Kazafuzan. In the following January 2010 tournament at sandanme he finally lost his first bout, having won all of his previous 16 matches. This would be his only loss though, and his 6–1 record was enough to propel him into the makushita division in the following March tournament. He again posted a perfect record and took the makushita championship. His meteoric rise would slow starting with his next tournament however. He only managed two wins in his next makushita tournament. This was his first losing tournament. In contrast to his previous successes, he struggled somewhat for several more tournaments at this level. He eventually had enough winning tournaments in upper makushita to allow his promotion into the professional jūryō ranks for the July 2011 tournament. He was promoted to the high rank of jūryō 4 due to the high number of vacancies left by wrestlers forced to retire due to involvement in match-fixing. At this high level he only managed a 7–8 record and moved down two ranks to jūryō 6 for the following September tournament. Suffering from a herniated disc, he was forced to sit out the first two days of the tournament, but managed to make a remarkable recovery and pulled out an impressive 10–3 record for his remaining bouts of the tournament.
Makuuchi career
Aoiyama's record was enough to allow him promotion to the top makuuchi division for November 2011. He posted an impressive 11–4 record and received a Fighting Spirit award for his efforts. He did, however, share this record with his rival, Wakakōyū having lost to him on the final day of the tournament.
In February 2012 Aoiyama's stablemaster died and Tagonoura stable was dissolved, with Aoiyama moving to the affiliated Kasugano stable. After an 8–7 score in the March tournament, he reached his highest rank to date of maegashira 6 in the May tournament, where he produced a fine 11–4 record. In the July tournament he faced all the top ranked wrestlers for the first time. Although he was 1–6 down after seven days, he recovered to clinch his kachi-koshi on the final day. In September he made his san'yaku debut at komusubi, which was just 18 tournaments after his professional debut, the seventh fastest since 1958. However, he could only win four matches. He was forced to withdraw from the November 2012 tournament on Day 9 with a knee injury. He picked up his first kinboshi or gold star for defeating yokozuna Harumafuji in September 2013.
He earned promotion to sekiwake with a strong 10–5 performance in September 2014 in which he went 4–3 against wrestlers ranked in the san'yaku. He then secured a winning record in the subsequent November tournament to remain at sekiwake for the start of 2015. A 5–10 record in January 2015 saw him lose his san'yaku status was followed by another ten losses in March, but he showed some return to form to post winning records in May and July. Between September 2015 and March 2016 he recorded four consecutive 7–8 records at the top end of the maegashira rankings before a 6–9 in May.