He made his K-1 debut at the K-1 World MAX 2007 Japan Tournament in one of the opening fights as the youngest contestant at the age of 15 on February 5, 2007.
[2] He moved up to 65 kg and stopped Chonden Chuwattana with low kicks just thirty seconds into round two at Big Bang 11 on December 2, 2012.
[3] He beat Keiji Ozaki by majority decision in a non-tournament bout at Krush Grand Prix 2013 ~67kg Tournament First Round~ on January 14, 2013 in Tokyo.
[4][5] Hiroya had his rubber match with Masaaki Noiri in the quarter-finals of the Road to Glory Japan -65kg Slam on March 10, 2013.
[9] He knocked out Igor Liubchenko with a second round high kick at MAX Muay Thai 5: The Final Chapter in Khon Kaen, Thailand on December 10, 2013.