As a young boy he attended an area sumo exhibition and had his picture taken sitting on the lap of future yokozuna Takanohana.

[3] He made a poor start to the tournament, losing eight of his first nine bouts, but he showed great strength of character in winning the last six in a row to finish with a 7–8 record and remain in san'yaku, albeit at the lower rank of komusubi.

It was initially reported that he would need ten days of rest, but his stablemaster (the former Kotonowaka) indicated that Kotoshōgiku was keen to return to action as soon as possible.

After this tournament he was named as one of seven wrestlers who NHK commentator Shuhei Nagao (the former Mainoumi) called the "Seven Samurai" and identified as "holding the key" to a Japanese resurgence in sumo, which was dominated by foreigners in the top ranks.

Despite admitting some involvement with gambling in the wake of the scandal surrounding his stablemate Kotomitsuki, it was not deemed serious enough to warrant a suspension.

Sumo Association official Takanohana indicated that Kotoshōgiku would be considered for ōzeki promotion if he won or came close to winning the following tournament in March.

Needing to win at least twelve bouts in July to be considered for ōzeki promotion,[7] Kotoshogiku seemed on course by Day 11 when he defeated Hakuho for just the second time to move to 9–2.

In the September 2011 tournament Kotoshōgiku put in another strong performance, faltering only against fellow sekiwake Kakuryū and maegashira Tochiōzan before beating Hakuhō for the second time in a row on Day 13.

In the event however, Kotoshōgiku lost his last bout to ōzeki Baruto while Hakuhō won to clinch his twentieth championship.

[10] He was injured again and withdrew early in the November 2013 tournament; after returning he had two mediocre performances followed by a very poor 5–10 in May 2014 and was kadoban, at risk of losing his ōzeki status.

In the July 2014 tournament, he responded with his best performance as an ōzeki, and was tied for the lead going into the final day before losing to Gōeidō and finishing 12–3.

In November he started strongly, winning seven of his first eight matches, but then began to struggle and withdrew injured on day 14 to end with an 8–6–1 record.

The January 2016 tournament marked ten years since Tochiazuma became the last Japanese-born wrestler to win the top-division title.

Kotoshōgiku began it with ten straight victories (including wins over Kisenosato and Kakuryū)[11] before attempting to take sole possession of the lead against the similarly undefeated Hakuhō on day 11.

[13] On day 13 his winning run ended as he sustained an upset loss to the maegashira Toyonoshima, a long-time friend.

His parents, who were in attendance, reportedly burst into tears whilst fans in his hometown of Yanagawa celebrated after watching his victory on a big screen.

On the third day of the September 2017 tournament he defeated Harumafuji, earning his first career kinboshi for an upset of a yokozuna while ranked as a maegashira.

[21] He was forced to withdraw from the July 2018 tournament after suffering a tendon injury in his left elbow during a defeat to Tamawashi on Day 10 in which he was thrown from the dohyo with a kotenage armlock throw.

[22] In March 2019 he was in contention for the Fighting Spirit prize but was defeated on the final day; however he still finished with a strong 11–4 record.

He was nominated for a fourth Outstanding Performance Prize as a result, but was defeated on the final day of the tournament and so missed out on the award.

[24] During the January 2020 tournament he tied with Takanohana on 701 top division wins, ninth place on the all-time list, and said he felt honoured to find his name next to him.

[25] He surpassed Takanohana and Musashimaru in the following tournament, and Harumafuji and Kisenosato in July, to rise to sixth place on the all-time list, finishing his makuuchi career with 718 wins.

Kotoshōgiku withdrew from the September 2020 tournament after a torn muscle in his lower left leg,[26] but returned from Day 7.

[30] Although the groundbreaking ceremony took place in November 2023,[31] the stable officially opened on 19 October 2024, with four wrestlers, all ranked in the jonidan division.

[citation needed] After marrying in the summer of 2015, the wedding reception was held on 30 January 2016, Kotoshōgiku's 32nd birthday, and just a week after his first tournament championship.

[35] His trademark was gaburi-yori, which involves using the torso to bump the opponent out, aided by a low centre of gravity and momentum.

Sanshō key: F=Fighting spirit; O=Outstanding performance; T=Technique     Also shown: ★=Kinboshi; P=Playoff(s) Divisions: Makuuchi — Jūryō — Makushita — Sandanme — Jonidan — Jonokuchi