The K-1 WORLD GP 2021 Japan Bantamweight Tournament takes place on May 30, 2021, at Yokohama Budokan in Yokohama, Japan. This kickboxing event features an eight-man Bantamweight Tournament with fighters like Toma Kuroda, Kazuki Miburo, Hinata Matsumoto, and Aoi Noda. The tournament concludes with Toma Kuroda facing Kazuki Miburo in the final. Additional bouts include Tatsuya Tsubakihara vs. Shuhei Kumura and Kenta Hayashi vs. Vitor Tofanelli.

The K-1 WORLD GP 2021 JAPAN ～よこはまつり～ takes place on September 20, 2021, at Yokohama Arena in Yokohama, Japan. This kickboxing event features Kenta Hayashi facing Daizo Sasaki in a super lightweight bout as a key matchup. Other fighters include Rukiya Anpo, Sina Karimian, and Hirotaka Asahisa across various weight classes. A special heavyweight bout marks Satoshi Ishii’s kickboxing debut against Ryo Aitaka.