Ryuya Kusakabe

Amateur career

Kusakabe took part in the super bantamweight (-55 kg) event of the 2008 K-1 Koshien Chūbu region tournament, open exclusively to high-schoolers, on July 6, 2008. He captured the tournament title with three consecutive unanimous decisions in a single day, as he was able to overcome Kosuke Minowa in the quarterfinals, Taishi Hiratsuka in the semifinals and Yusuke Tsuboi in the finals.^[3]

This success earned him a place in the K-1 Koshien King of Under 18 Tournament, the opening round of which was held in Tokyo, Japan on October 1, 2008. Kusakabe beat Ryuma Tobe by unanimous decision in the opening round and future two-weight Krush champion Daizo Sasaki by a first-round knockout in the quarterfinals. He advanced the to tournament semifinals, held on December 31, 2008, where he suffered a third-round technical knockout stoppage at the hands of the future two-weight K-1 champion Koya Urabe.^[4]

Early professional career

Kusakabe made his debut as a professional competitor against Phetsanga Sakrungruang on March 16, 2008, at the famed Rajadamnern Stadium. He won the fight by a fourth-round technical knockout and went on to win two more fights before making his AJKF and Krush debuts against Rikiya Ozawa at AJKF Krush.3 on May 17, 2009. Kusakabe won the fight by unanimous decision, with all three judges awarding him a 30–27 scorecard.^[5] Kusakabe next faced the one-time AJKF Super Bantamweight title challenger Shota Takiya at Krush×Survivor on March 13, 2010. He won the fight by majority decision. Two of the judges scored the bout 30–29 and 30–28 in his favor, while the third ringside official handed in an even 30–30 scorecard.^[6]

Shootboxing champion

On March 30, 2010, it was revealed that Kusakabe would be one of eight participants in the Shootboxing Young Caesars Super Bantamweight tournament, with the eventual winner being guaranteed a title shot.^[7] Kusakabe faced Masahiro Fujimoto in the tournament quarterfinals at "Anniversary Series 2 -ISHIN- So no Ni" on April 11.^[8] The bout was judged a majority draw after the first three rounds were contested. Two of the ringside officials scored the contest 29–29, while the third judge edged it 29–28 for Kusakaba, who was declared the winner by unanimous decision after an extra fourth round was fought.^[9]

Kusakabe faced Masanori Minato in the Young Caesars tournament semifinals at "Anniversary Series 3 -ISHIN- So no San" on June 6, 2010.^[10] He won the fight by a third-round technical knockout and advanced to the Ceasers Cup final, held on the same day, where he faced Kazuyuki Fushimi, who he had beaten by unanimous decision two years prior. Kusakabe was even more successful in the rematch, as he was able to knock Fushimi out with a hook to the body at the 1:35 minute mark of the final round.^[11]

The tournament victory earned Kusakabe the right to challenge Phantom Shinya for the Shootboxing Japan Super Bantamweight Championship at "Anniversary Series 4 -ISHIN- So no Yon" on September 18, 2010.^[12] He won the fight by a third-round technical knockout to become the youngest champion in Shootboxing history at the age of 18 years and two months, breaking the record previously held by Makoto Ue by a month.^[13]

Krush tournament run

On November 11, 2010, it was announced that Kusakabe would be taking part in the Krush Super Bantamweight Inaugural Championship Tournament. Kusakabe faced the former AJKF and RISE bantamweight champion Nobuchika Terado in the quarterfinals, which were held on December 12, 2010.^[14] He won the fight by unanimous decision.^[15] Kusakabe faced Hiroaki Mizuhara in the tournament semifinals on April 30, 2011. He won the fight by unanimous decision and advanced to the final, held on the same day, where he faced Shota Takiya for the inaugural Krush Super Bantamweight title. Kusakabe suffered the first loss of his professional career, as Takiya was able to stop him with a front kick, near the end of the third and final round.^[16]