[1] He represented Japan in the marathon at the 2012 Summer Olympics and the 2011, 2013 and 2017 World Championships in Athletics, finishing in the top ten on all four occasions.

He began to feature in high level races while attending Takushoku University and ran at the 2005 Hakone Ekiden.

He was Asia's second fastest performer, after his teammate Hiroyuki Horibata, with whom he secured the team silver medals in the 2011 World Marathon Cup.

[9] A return to the Lake Biwa race in 2012 saw him finish in the same position, but in a personal best of 2:08:53 hours (the second Japanese behind Ryo Yamamoto).

[13] Nakamoto began 2013 with a personal best of 2:08:35 hours at the Beppu-Ōita Marathon, taking the runner-up spot behind Yuki Kawauchi, who broke the course record to win.