fight Shuhei Kumura in a non-title bout at K-1 World GP 2021: Japan Bantamweight Tournament. Tsubakihara won the fight by unanimous decision, with the judges scoring the fight 30－29, 30－28 and 30－29 in his favor. Tsubakihara was scheduled to make his first K-1 Featherweight title defense against the former two-time Krush Super Bantamweight title challenger Taito Gunji at K-1 World GP 2021 Japan on December 4, 2021. Tsubakihara and Gunji fought four times previously, with each holding a single win and loss against the other as amateurs and professionals. Tsubakihara lost the fight by split decision. The fight was ruled a split draw after the first three rounds were contested, with one judge each awarding Tsubakihara and Taito a 30-29 scorecard respectively, while the third judge scored it a 30-30 draw. The judges were once again split after an extra round was fought, with one judge scoring it 10-9 for Tsubakihara, while the remaining two judges scored it 10-9 for Taito. Post title reign Tsubakihara faced the Krush Featherweight champion Takahito Niimi at K-1: K'Festa 5 on April 3, 2022. He won the fight by unanimous decision. Two of the judges scored the bout 30–29 in his favor, while the third judge awarded him a 30–28 scorecard. Tsubakihara faced the one-time Krush featherweight title challenger Toma Tanabe in the quarterfinals of the 2022 K-1 Featherweight World Grand Prix at K-1 World GP 2022 in Fukuoka on August 11, 2022. He lost the fight by a narrow majority decision. Two of the judges scored the fight 30–29 for Tanabe, while the remaining judge scored it as an even 30–30 draw. Tsubakihara faced Shoki Kaneda at K-1 World GP 2022 in Osaka on December 3, 2022. He lost the fight by unanimous decision, with all three judges scoring the fight 30–26 for Kaneda. Tsubakihara was knocked down with a left hook in the second round, which led to all three judges scoring the round 10–8 for Kaneda. Titles and accomplishments Professional K-1 2021 K-1 World GP Featherweight Championshipn Amateur 2017 K-1 Koshien ‐55 kg Champion 2016 K-1 Koshien -55kg Runner-up 2015 K-1 Koshien -55kg Runner-up 2015 K-1 Challenge A-Class -60 kg Tournament Winner 2012 Kyoken Junior Kick Middleweight Champion (3 Defenses) Awards 2017 K-1 Awards Rookie of the Year 2020 Combat Press Upset of the Year Kickboxing record |- style="background:#fbb" | 2022-12-03|| Loss ||align=left| Shoki Kaneda || K-1 World GP 2022 in