Bellator Kickboxing On June 24, 2016, Kato made his professional kickboxing debut for
Bellator Kickboxing. He faced
Joe Schilling in a rematch at
Bellator Kicking 2. Despite Schilling being the more experienced kickboxer, Kato again won the fight by knockout due to a spinning back fist in the second round.
K-1 Kato was scheduled to face
Makoto Uehara for his K-1 debut. He beat Uehara by decision, after an extra round was fought. In his second fight with K-1, Kato was scheduled to fight RUI. Kato won the fight by a first-round KO. Kato challenged for the K-1 Cruiserweight title, held at the time by
Sina Karimian, during K-1 K'Festa 2. He lost the fight by a unanimous decision. After his failed title shot, Kato was scheduled to fight
K-Jee in December 2019. He won the fight by a second-round KO. The two of them fought a rematch during Krush 112, for the Krush Cruiserweight title. K-Jee won the fight in the first round, by a body shot KO. For his sixth fight with K-1, Kato was scheduled to fight
Mahmoud Sattari at
K-1: K’Festa 4. He lost the fight by a second-round knockout, suffering a broken nose in the process. Kato faced
Ryo Aitaka at
K-1: K'Festa 5 on April 3, 2022, in the reserve bout of the 2022 K-1 openweight tournament. He won the fight by a third-round knockout. As
Satoshi Ishii later withdrew from the tournament due to injury, he stepped in as the replacement to face Seiya Tanigawa in the tournament semifinals. He lost the semifinal bout by a first-round knockout. Kato faced Akira Junior at
K-1 World GP 2022 in Osaka on December 3, 2022. Despite scoring a knockdown in the first round, he lost the fight by a second-round knockout. ==Championships and accomplishments==