Ota began participating in major international and domestic wrestling tournaments while attending the Nippon Sport Science University. As a third-year student he won the Hungarian Wrestling Grand Prix, and as a fourth-year student he won the Emperor's Cup.[2]
Ota took part in the 2016 Asian Olympic qualifier tournament, held between March 18–20, 2021, competing in the 59 kg Greco Roman event. He was scheduled to face the six-time world champion and 2012 Olympic gold medalist Hamid Sourian in the opening round. Despite coming into the match as a significant underdog, Ota pulled off an upset victory, beating Sourian 7–4 on points.[3] Ota would furthermore beat Phils Tuktaev in the quarterfinals and Kim Seung-Hak in the semifinals, before losing to Wang Lumin in the finals. Despite this loss, he won the right to participate in the Olympic Games.[4]
Ota was scheduled to fight a rematch with Hamid Sourian in the opening round of the 2016 Olympic games. Despite losing 4-0 by the end of the first half of the match, Ota mounted a comeback in the second half, winning by 6–5 on points. He beat Almat Kebispayev 6–0 in the next round, Stig-André Berge 4–0 in the quarterfinals and Rovshan Bayramov in the semifinals, which guaranteed him the silver medal.[5] Ota faced the Cuban Ismael Borrero in the final match, and lost by technical fall.[6]
Ota won the 2018 Asian Games 60 kg Greco-Roman event.[7]
Ota participated in the 2019 All-Japan Selection Championship for the 2020 Olympic Games, taking part in the 60 kg Greco-Roman event. He lost to the 2019 World Championship winner Kenichiro Fumita 1–4 in the finals.[8] As this rendered him unable to participate in the Olympic Games, Ota opted to take part in the 67 kg Greco-Roman event as well.[9] He lost the very first match.[10]
Mixed martial arts career
Following his retirement from wrestling competition, he signed with Rizin Fighting Federation.[11] Tokoro made his professional debut against Hideo Tokoro at Rizin 26 on December 31, 2020.[11] He lost the fight by a second-round armbar.[12]
Ota faced the former K-1 Welterweight champion Yuta Kubo at Rizin 30 on September 19, 2021.[13] He won the fight by unanimous decision.[14]
Ota faced 46-fight veteran Kazuma Sone at Rizin 33 - Saitama on December 31, 2021.[15] He won the fight by a second-round technical knockout.[16]
Ota faced the former DEEP bantamweight champion Yuki Motoya at Rizin 37 - Saitama on July 31, 2022.[17] He lost the fight by unanimous decision.[18]
Ota faced Kazuma Kuramoto at Rizin Landmark 5 on April 29, 2023.[19] He knocked Kuramoto out just 27 seconds into the opening round.[20]
Ota faced Kenta Takizawa at Super Rizin 2 on July 30, 2023, winning the fight by a first-round knockout at the end of the round.[21]
Ota faced Shoko Sato at Rizin Landmark 6 on October 1, 2023, losing the fight by split decision. [22]
Ota faced Juntaro Ushiku at Rizin 46 on April 29, 2024.[24] He won the fight by unanimous decision.[25]
Ota was scheduled to face Francesco Nuzzi, replacing Brian Moore on June 22, 2024, at Bellator Champions Series 3.[26] However, Nuzzi was replaced by Blanque; Ota won the bout by a north-south choke submission in the first round.[27]
Ota faced Yuki Motoya at Rizin 48 on September 29, 2024, and lost the bout via submission in the third round.[28]
