[citation needed] After winning the All-Japan Amateur Boxing Championships in the first grade of university in 2004, he captured the bronze medal in the 2005 Asian Amateur Boxing Championships in Ho Chi Minh City,[3] and the silver medal in the 2005 King's Cup in Bangkok.

[citation needed] At the 2008 1st Asian Olympic Qualifying Tournament in Bangkok, Thailand, he won over Narmandakh Shinebayar in the quarterfinal but lost to Elshod Rasulov in the semifinal.

In the 2nd AIBA Asian 2008 Olympic Qualifying Tournament in Astana, Kazakhstan, he was eliminated in the quarterfinal by Homayoun Amiri and ended in the seventh place.

In the 2010 Kazakhstan President's Cup in Astana, he won over Levan Guledani in the preliminary round but lost to Danabek Suzhanov in the quarterfinal.

[23] Murata's run came to an end against Evhen Khytrov, losing a close match (22–24) and taking home the silver medal.

[2] In the 2012 Summer Olympics, second-seeded Murata defeated Algeria's Abdelmalek Rahou 21–12 in the round of 16 at the ExCeL London on 2 August 2012.

[35] Men's Middleweight (75 kg) Murata registered with Misako Boxing Gym in April 2013,[36] and signed with Top Rank in June.

[37] Before turning professional, Murata had declined participation in AIBA Pro Boxing by saying that he intended to retire as a boxer.

[39][40] Upon turning professional, Murata was banned from Japan Amateur Boxing Federation (JABF) for his disloyal behavior in February 2013.

[42] His professional debut took place in a six-round bout at a 161 lb catchweight against Akio Shibata at the Ariake Coliseum on 25 August 2013.

[45] After 12 consecutive victories, Murata fought for the vacant WBA (Regular) title against Hassan N'Dam N'Jikam on 27 May 2017.

[46] The two judges who scored the fight for N'Dam N'Jikam were immediately suspended and WBA president Gilberto Mendoza issued a public apology.

[53] Murata failed to defend his WBA middleweight world title and suffered his second defeat on 20 October in Las Vegas, losing to mandatory challenger Rob Brant of the U.S. by unanimous decision, 118-110, 119-109 and 119-109.

[55] Brant made his second defense of WBA "regular" middleweight title against Murata on 12 July 2019 at Edion Arena in Osaka, Japan.

[57] Murata defended his regained title on 23 May December 2019 at the Yokohama Arena against hard-punching Canadian contender Steven Butler (27-1).

Murata's power showed up right from the start, but Butler managed to keep up with the champion in the early rounds using his long reach and fast combinations.

However, Murata's constant offense, sharp jab and powerful rights started to wear down Butler in round four.

Referee Rafael Ramos immediately halted the contest, thus giving Murata the victory by TKO.

[60] After multiple rumors suggesting that Murata was set to take on IBF and IBO champion Gennady Golovkin in a unification match, it was announced on 27 October 2021 that a deal had finally been agreed between the two to stage the bout at the Saitama Super Arena in Saitama, Japan on 29 December 2021.