Yamanaka started his career aged 17 on June 2012. His career record to date stands at 7-2-0 with a mixed bag of results so far in the career. Yamanaka's longest KO streak is 1 fights long out of his 9 pro career fights.
Showing his superior boxing ability in an impressive debut, Yamanaka picked up the win against Kazuki Koyanagi and became only one of 5 people to have taken him the full 4 round distance. Following on from his debut, Yamanaka continued his career by fighting in a further 5 fights. In this time he fought Junpei Omori, Takayuki Teraji and Kazuki Koyanagi to name just a few, fighting 3 times in 2012 and 2 times in 2013 in this period.
On April 21st, 2013, Yamanaka took on and was defeated by Kenta Shimizu in his first career defeat meaning his career tally went to 4-1-0. Yamanaka's fight against Kenta Shimizu was Yamanaka's first stoppage defeat of his career. This came via KO in the 1st round of a 4 round fight.
Yamanaka went into his next career fight with a record of 4-1-0 and took this to 5 wins with a win against Masaki Hirai on July 12th, 2013. Hirai was a worthy challenger but Yamanaka was too much and became the first person to stop Hirai via TKO during round 4. Yamanaka then went on to win again against Junya Nishikawa setting him up well for his next pro fight.
Pushing his career further, Yamanaka fought Hiroki Yamamoto on April 6th, 2014 adding to his winning record. Yamanaka secured the win over Yamamoto after the final bell via UD, resulting in Yamanaka being the 10th person to defeat Yamamoto.
The next defeat of Yamanaka's career came against Roque Lauro on August 22nd, 2014. This took his career record to 7-2-0. Fighting over a competitive 8 round bout, Yamanaka was outclassed in his most recent outing taking a SD loss over the distance at the hands of Lauro.