After winning by ippon and two yukos in both round of 64 and 32, he lost by waza-ari to Canada's Nicholas Tritton, ending his first IJF outing in his third fight.

At the Grand Prix in Rotterdam, Nakaya failed to win a medal when he lost to Poland's Tomasz Adamiec by two waza-aris in the quarter-final.

He defeated the Netherlands' Dex Elmont in the quarter-final,[9] fellow Japanese Yasuhiro Awano in the semi-final, and Hungary's Attila Ungvari in the final, all by ippon, giving him his second IJF circuit and Grand Slam title.

Nakaya reached the semi-final of the World Cup in Budapest, and lost to Ungvari in a revenge match by ippon.

He reached the final after winning all his fights by ippon, but was faced against double world champion Wang Ki-chun, and lost by waza-ari, leaving him to settle for silver.

[12] Nakaya surprisingly failed to win a medal at his first outing as world champion at home ground at the 2011 Grand Slam in Tokyo.

In a turn of events, it was again a score-less fight, and Wang would be the one to defeat Nakaya by shido, leaving him to settle for silver.

[15] At the Olympics, Nakaya defeated his first two opponents by ippon, and scraped through to the final by beating Tajikistan's Rasul Boqiev by yuko, and Elmont by shido.

[16] Nakaya was one of Japan's three silver medalists, and with only Kaori Matsumoto winning gold, it was the country's worst judo campaign at the Olympics.

[17] Nakaya continued his losing streak at the 2012 Grand Slam in Tokyo, where he lost to rising star Ono in the final by ippon and waza-ari.

At the 2013 World Championships, Nakaya defeated his first two opponents by ippon, and then won against Taipei's Huang Chun-ta by waza-ari.

[22] At the Grand Slam in Paris in 2014, just six months before the world championships, Nakaya experienced a set-back when he was defeated by Isaev by ippon in the second round.

[24] At the 2014 World Championships, Nakaya came in ranked number sixteen, and had a difficult match list with budding stars like Israel's Sagi Muki[25] and Azerbaijan's Rustam Orujov.

Nakaya then faced 2013 Asian Champion Hong Kuk-hyon, ranked number 32, in the final, who had equally difficult opponents in the form of Dirk Van Tichelt, Nugzar Tatalashvili and Ugo Legrand.

[29] Nakaya then competed in his fourth world championships in Astana, where he played ippon judo en route to the final.

He lost against eventual finalist Akimoto in the quarter-final by ippon,[34] then had to concede in the bronze medal contest against Muki due to a broken arm, leaving him to finish fifth place.