Nakano made his international debut at the 2002 Asian Games in Busan, South Korea, where he earned a silver medal in the 200 m backstroke, clocking at 2:00.78.

[6] At the 2005 FINA World Championships in Montreal, Quebec, Canada, Nakano broke the two-minute barrier, but rounded out the final field in last place by 0.17 of a second behind Croatia's Gordan Kozulj in 1:58.91.

[7] Nakano also improved his personal best to 1:59.34, adding a bronze to his silver from Busan in the same stroke at the 2006 Asian Games in Doha, Qatar.

[9] He challenged seven other swimmers on the fourth heat, including Austrian duo Sebastian Stoss and two-time Olympic silver medalist Markus Rogan.

[10] At the 2009 FINA World Championships in Rome, Italy, Nakano broke his personal best of 1:57.02 in the 200 m backstroke, but finished only in twelfth place and did not qualify for the final.