second-round knockout. His last fight outside of K-1 was against Jin Mandokoro at Hoost Cup Kings Kyoto 2. Tsubakihara won the fight by unanimous decision. Tsubakihara was scheduled to make his K-1 debut at KHAOS 2, against Taito Gunji. The two of them fought twice as amateurs, trading wins and losses. Tsubakihara won their first professional meeting by majority decision, with two of the three judges scoring the bout in his favor. Tsubakihara was scheduled to fight Haruma Saikyo at K-1 Survival Wars. The two of them fought previously in the finals of the 2015 K-1 Koshien tournament, with Saikyo winning by split decision. Tsubakihara won the fight by majority decision. Tsubakihara was scheduled to fight the future Krush Super Bantamweight champion Masashi Kumura at Krush 86. Tsubakihara lost the fight by unanimous decision, with all three judges scoring the bout 30-26 for Kumura. Tsubakihara was scheduled to fight Riku Morisaka at KHAOS 5. He won the fight by unanimous decision, with two of the judges scoring the bout 30-28 for Tsubakihara. Krush Super Bantamweight tournament His 3-1 record earned Tsubakihara a place in the 2018 Krush Super Bantamweight tournament, being scheduled to fight Yusho Kanemoto in the quarterfinal bout at Krush 93. The other tournament pairings pitted Taito Gunji against Riku Morisaka, Shota Oiwa against Masashi Kumura and Shoya Masumoto against Victor Saravia. Tsubakihara won the fight by a second round technical knockdown, managing to knock Kanemoto down three times. The first knockdown came as Tsubakihara countered Kanemoto's step-in knee with a right straight, the second knockdown came as a result of another right straight, while the third knockdown came as a result of a combination of punches after Kanemoto was pressured into a corner. Tsubakihara advanced to the tournament semifinals, where he was scheduled to fight Taito Gunji at Krush 96. It was their fourth overall career meeting, with Tsubakihara winning two of their previous three meetings. The fight was as close as their previous three bouts, with Gunji winning a split decision, after an extra round was fought. Later Super Bantamweight career Tsubakihara was scheduled to fight Ryuto at Krush 100. He won the fight by majority decision, with one judge scoring the bout 29-29, while the remaining two judges scored the fight 30-28 for Tsubakihara. Tsubakihara was scheduled to fight Aoshi at the K-1 World GP 2019: Japan vs World 5 vs 5 & Special Superfight