Kazuki Osaki

Osaki made his professional debut against Yuzuki Sakai at MUAYTHAI WINDY SUPER FIGHT. He won the fight by unanimous decision.[4] He won his next fight against Kaito Gibu as well, before suffering his first professional loss to Banfus Hunter at MUAYTHAI WINDY SUPER FIGHT vol.17.[5] Osaki would go on to amass a 7-1-2 (1) record, before fighting Yuya Kosaka for the WMC Japan Flyweight title at Muay Lok 2017 1st. He won the fight by unanimous decision.[6]

Osaki won his next six fights, including four straight victories at the Lumpinee Stadium. He was scheduled to defend his WMC title for the first time against Taiga Nakayama at The Battle Of Muaythai 17.[7] Osaki won the fight by majority decision.[8] In his next fight he won the Lumpinee Stadium of Japan Flyweight title, with a knockout of Tatsuya Hibata. He afterwards fought Kiew Parunchai for the Lumpinee Stadium 112 lbs belt, but lost the fight by decision.[9]

Osaki made his KNOCK OUT debut against Tatsuya Noto at KNOCK OUT SUMMER FES.2018 on August 19, 2018, in the quarterfinals of the 2018 flyweight tournament, held to crown the King of Knock Out flyweight champion. He won the fight by a second-round technical knockout, knocking him down twice before the referee waved the fight off.[10] Osaki advanced to the tournament semifinals, held at KNOCK OUT 2018 cross over on October 7, 2018, where he faced Yoshiho Tane. He won the fight by a fifth-round technical knockout.[11] Osaki faced Issei Ishii at KING OF KNOCK OUT 2018 on December 9, 2018, in the finals of the tournament.[12] He lost the fight by a narrow majority decision. Two of the judges scored the fight 49–48 for Ishii, while the third judge scored it as an even 49–49 draw.[13]

Osaki made his fourth appearance with the promotion against Chokdee PK.Saenchaimuaythaigym at KNOCK OUT 2019 WINTER on February 11, 2019. He lost the fight by unanimous decision, with two scorecards of 49–46 and one scorecard of 48–46.[14]

Osaki returned to Hoost Cup to face KING Takeshi at HOOST CUP KINGS NAGOYA 6 on May 26, 2019.[15] He won the fight by unanimous decision, after an extra fourth round was contested.

Osaki faced the former two-time Krush Super Bantamweight champion Shota Takiya at Rizin 18 - Nagoya on August 18, 2019.[16] He won the fight by a wide unanimous decision. Osaki knocked Takiya down twice, first with a left hook to the body in the second round and the second time with a right hook in the third round.[17]

Osaki faced Koudai Hirayama at HOOST CUP KINGS OSAKA 4 on October 27, 2019. He won the fight by a close majority decision, with scores of 30–29, 29–29 and 30–29.[18]

Osaki faced Konesarn Acegym at Norainu Matsuri 6 Shin Kiba 1st Ring on January 19, 2020. He stopped Konesarn with low kicks at the 2:53 minute mark of the opening round.[19]

Osaki made his RISE debut against Kazane, who entered the fight on a five-fight winning streak, at RISE 137 on February 23, 2020.[20] He won the fight by unanimous decision. Two of the judges scored the fight 29–27 in his favor, while the third judge awarded all three rounds of the bout to him. Osaki knocked his opponent down with a right hook midway through the second round.[21]

Osaki faced the #1 ranked RISE super flyweight contender Jin Mandokoro at RISE 140 on July 19, 2020, in a title eliminator bout.[22] The fight was ruled a majority decision draw after the first three rounds were contested, with one judge scoring the bout 29–28 for Osaki. Osaki was awarded a majority decision win after an extra fourth round was contested.[23]

Osaki, who as at the time the top ranked contender, challenged Toki Tamaru for the RISE Super Flyweight (-53 kg) Championship at RISE 142 on September 4, 2020. Due to measures implemented to combat the COVID-19 pandemic, only a limited audience of 700 people was allowed into the Korakuen Hall, where the title bout took place.[24] Osaki captured the title by unanimous decision. Two judges scored the fight 49–47 in his favor, while the third judge scored it 50–47 for him.[25][26]

Osaki faced the Shootboxing Japan bantamweight champion Kyo Kawakami in a non-title bout at RISE 143 on November 14, 2020. He beat Kawakami by unanimous decision, with scores of 30–29, 29–28 and 30–28.[27][28]

Osaki faced the WMC and WBC Muaythai bantamweight champion Ikko in a non-title bout at RISE 146 on February 23, 2021. He won the fight by unanimous decision, with two scorecards of 29–28 and one scorecard of 30–28.[29] Osaki was next expected to face Shiro at "Rise on Abema" on May 15, 2021, in a bantamweight (-55 kg) bout.[30] His brother Koki Osaki tested positive for COVID-19 on May 12, which led to the fight being scrapped as a preventive measure.[31]

Osaki faced Issei Ishii at RISE WORLD SERIES 2021 Osaka on July 18, 2021, in the quarterfinals of the 2021 RISE Dead or Alive 53 kg tournament. The pair previously fought on December 9, 2018, with Ishii winning by majority decision.[32] Osaki won the rematch by unanimous decision, with scores of 29–28, 29–28 and 29–27. He scored the sole knockdown of the fight in the second round, as he dropped Ishii with a left hook.[33] Advancing to the tournament semifinals, Osaki was expected to face Shiro at RISE WORLD SERIES 2021 Yokohama on September 23, 2021, in the tournament semifinals.[34] Osaki withdrew from the bout with an ankle injury on August 24, and was replaced by his brother Koki Osaki.[35]

Osaki was booked to face Kanta Tabuchi in a non-title bout at RISE 156 on March 27, 2022.[36] He won the fight by majority decision, with scores of 30–29, 30–29 and 30–30.[37] Osaki then faced Sanchai TeppenGym in another non-title bout at RISE WORLD SERIES 2022 Osaka on August 21, 2022.[38] He won the fight by a third-round knockout.[39]

Osaki made his first RISE super flyweight (-53  kg) title defense against the 2021 RISE super flyweight Dead or Alive Tournament winner and the number one ranked contender Kazane at RISE Word Series 2022 on October 15, 2022.[40] He won the fight by a narrowly contested majority decision, with scores of 50–49, 48–48 and 49–48.[41]

Osaki was booked to face Mangkon Boomdeksean in a non-title bout at RISE 164 on January 28, 2023.[42] He won the fight by a third-round technical knockout. Osaki knocked Mangkon down three times inside of single round, which forced the referee to stop the contest.[43]

Osaki faced Javier Cecilio at RISE ELDORADO 2023 on March 26, 2023.[44] He won the fight by a first-round knockout.[45] During his post-fight speech, Osaki asked for a fight with one of the flyweight ISKA world champions, as well as a place in the upcoming RISE -54 kg World Series tournament.[46] His wish was granted, as he was booked to face Nicolas Rivas for the vacant ISKA Oriental rules World Flyweight (-53.5 kg) championship at RISE 167 on April 21, 2023.[47] Osaki stopped Rivas with a spinning heel kick 28 seconds into the fourth round.[48]

Osaki was expected to face the ISKA K-1 Super Flyweight (-55 kg) World champion Frederico Cordeiro in the quarterfinals of the 2023 RISE -54 kg World Series, held on July 2, 2023.[49] Corderiro withdrew with an injury suffered in training camp on June 23 and was replaced by the 17-year old Aiman Lahmar.[50] Osaki was able to thrice knock Lahmar down with low kicks in the second round, which resulted in a technical knockout victory for him under the RISE rules.[51]

Osaki faced the RISE Flyweight champion Toki Tamaru in the tournament quarterfinals on August 26, 2023. He beat Tamaru three years prior, by unanimous decision, to capture the RISE Super Flyweight title.[52] Osaki lost the rematch by majority decision, with scores of 30–28, 29–29 and 30–29.[53]