After graduating from high school he started working in construction, and became a painter to coat buildings with coloured acrylic resin.

[7] On July 31, 2005, he made his debut as a professional kickboxer in the RISE organization, and he knocked out Eiji Ogawa in the first round with a left low kick.

His second fight was on September 24 at NJKF "Infinity Challenge VIII" against Takuya Minekawa, which he won by a third-round technical knockout.

[11] He fought against Hanawa in the tournament title at NJKF "Start Of New Legend IX" on July 27, 2008, and he knocked him out in the first round with a left hook.

[16] On March 14, 2010, Yamato fought against Saenchai Sor Kingstar from Thailand in Los Angeles, US to challenge the vacant world lightweight title sanctioned by Muay Thai Association of America.

Yamato was awarded the unanimous decision after the extra fourth round was contested, with all three judges scoring the bout 10–7 in his favor.

[19] Yamato faced the RISE super featherweight champion Yuki in the quarterfinals of the Japan Tournament final, which took place on July 5, 2010.

[24] He returned to his winning ways in his next fight, as he overcame Makoto Nishiyama by a second-round technical knockout at New Japan Blood 3 on May 21, 2011.

[32] Yamato won his next bout as well, as he beat Sergio Wielzen by unanimous decision at Hoost Cup: Feast of the Kings on May 20, 2012.

[33] Yamato challenged the WBC Muay Thai Japan Super Lightweight champion Seiji Takahashi at NJKF: Kick to the Future 3 on June 24, 2012.

[35] He was scheduled to face Leo Monteiro for the vacant WBC Muaythai International Super Lightweight Championship on September 22, 2012, at NJKF's Kick to the Future 6 in Tokyo, Japan.

[37] After suffering a technical knockout loss due to cut to Sagetdao Petpayathai on May 16, 2013, Yamato was booked to face Kevin Ross at Lion Fight 11 on September 20, 2013.

[39][40][41] Yamato made his first WBC Muaythai International Super Lightweight title defense against Masaaki Noiri at NJKF 2014 1st on February 16, 2014.

[42] Yamato challenged the WBC Muaythai World Super Lightweight champion Sagetdao Petpayathai at NJKF 2014 8th on November 15, 2014.

[46] Following this stumble, Yamato made his maiden WBC Muaythai World Super Lightweight title defense against Aranchai Kiatpatarapan at NJKF 2015 6th on September 27, 2015.

[55] Yamato extended his win streak to three consecutive fights with a first round knockout of Jun Nakazawa at K-1 World GP 2017 Heavyweight Championship Tournament on November 23, 2017.

[56] These three victories earned Yamato the right to challenge for the title, as he was booked to face the K-1 Super Lightweight champion Masaaki Noiri at K-1 World GP 2018: K'FESTA.1 on March 21, 2018.

[64][65] Yamato was scheduled to face Hideaki Yamazaki for the K-1 World GP Super Lightweight Championship at K-1: K'Festa 5 on April 3, 2022.

[68] Yamato made his first title defense against the Krush Super Lightweight champion Daizo Sasaki at K-1 World GP 2022 Yokohamatsuri on June 17, 2022.

[70] Yamato made his second title defense against the one-time K-1 Lightweight champion Kenta Hayashi at K-1 World GP 2023: K'Festa 6 on March 12, 2023.

[73] Yamato faced the former Lumpinee Stadium super-featherweight champion Kaewkangwan Sithporkae at Suk Wanchai MuayThai Super Fight on June 30, 2024.