Born and raised in Shizuoka, Sasaki was a talented wrestler and also began training in Brazilian jiu-jitsu from a young age. He wrestled for three seasons at Hiryū High School, finishing in the top 16 at the All-Japan High School Greco-Roman Wrestling Championships, and in 2009 Sasaki won the All-Japan Combat Wrestling Open Championships for the under 66 kg division. That same year, he also finished second at the All-Japan Amateur Shooto Championships. Later in 2013, Sasaki won the ADCC Japan Trial for the under 66 kg division.[3]
Mixed martial arts career
Shooto
Sasaki started his professional career in 2010. He fought mainly for Shooto, but also fought for Deep and GCM early in his career. Sasaki faced Yo Saito on December 18, 2010, at Shooto: The Rookie Tournament 2010 Final. He defeated Saito via unanimous decision after two rounds and became the 2010 Shooto 143-pound rookie champion.[4]
Sasaki faced Tetsu Suzuki on January 20, 2013, at Shooto: 1st Round 2013 for the Shooto Pacific Rim 132-pound title. He won via unanimous decision and became the new champion.[5] Sasaki defended his title on July 27, at Shooto: 3rd Round 2013 against Kenji Yamamoto. He won via knockout at 11 seconds in the first round and retained the title. Shortly after the bout, Sasaki relinquished his title in order to be able to fight for Shooto's world title.[6]
Sasaki faced current ZST 132 lb champion Keisuke Fujiwara[7] on January 13, 2014, at Shooto: 1st Round 2014. He won via submission due to a rear-naked choke in the first round.[8]
Ultimate Fighting Championship
In July 2014, it was announced that Sasaki had signed with the UFC. He made his debut against Roland Delorme at UFC Fight Night 48 on August 23, 2014.[9] Sasaki won via submission in the first round. The win also earned Sasaki his first Performance of the Night bonus award.[10] Sasaki faced Leandro Issa on December 20, 2014, at UFC Fight Night 58.[11] He lost the fight by submission in the second round.
Sasaki faced Willie Gates May 8, 2016, at UFC Fight Night 87.[14] He won the fight via submission in the second round.[15] Sasaki was expected to face Matheus Nicolau on November 19, 2016, at UFC Fight Night 100.[16] However, on November 3, Nicolau was pulled from the bout after USADA revealed a potential anti-doping violation from a sample taken October 13.[17]
Sasaki faced Manel Kape in a 130lbs catchweight bout at Rizin 14 on December 31, 2018.[32] He won the fight by unanimous decision.
Sasaki was then scheduled to face Kai Asakura at Rizin 15 on April 21, 2019. However, Sasaki was forced to withdraw from the bout due to a visceral injury and was replaced by Justin Scoggins.[33] He then faced Shintaro Ishiwatari at Rizin 17 on July 28, 2019.[34] Sasaki lost the fight via second-round submission.[35] The fight with Kai Asakura was then rebooked to take place at Rizin 19 on October 12, 2019.[36] Sasaki lost the fight via first-minute technical knockout due to a broken jaw.[37]
After recovering from two jaw surgeries to repair the damage sustained in his previous fight, Sasaki faced Kenta Takizawa at Rizin 26 on December 31, 2020.[38][39] He won the fight via unanimous decision.[40]
Sasaki faced Yoshinori Horie at Rizin 30 on September 19, 2021.[41] He lost the bout via unanimous decision.[42]
Sasaki headlined Rizin Trigger 2 on February 23, 2022 against Kleber Koike Erbst.[43] Even after finding initial success with the stand-up in the first round, Sasaki lost the bout in the second round via rear-naked choke.[44][45] Sasaki was expected to face Yoshiki Nakahara at Rizin 37 on July 31, 2022. He withdrew from the fight on July 26, after he tested positive for COVID-19.[46]
Sasaki faced Boyd Allen at Rizin 42 on May 6, 2023. He won the fight by unanimous decision.[47]
Professional wrestling career
Pro Wrestling Noah (2023–present)
On October 23, 2023, Sasaki himself made an announcement that he would be participating in an exhibition match for Pro Wrestling Noah's November 13 episode of Monday Magic. In a statement made during the October 23 show, he specified that it had been a long-held aspiration of his to perform in Noah, as he had been a devoted fan of the promotion since childhood. He then conveyed on social media that he would "throw all of [his] soul" to enable him to compete in professional wrestling.[48]
On September 13, 2024, at Destination 2024, he defeated Hayata via referee stoppage to win the GHC National Championship, claiming his first wrestling title. His victory, achieved just six months after his debut, set a record for the fastest title win in the history of the championship.[50]
His ring name "Ulka" originates from Sanskrit and means "Tengu". He has expressed his fondness for this mythical creature and often wears a long-nosed Tengu mask during his professional wrestling entrances.[52][1]
In a November 2023 interview, he stated that witnessing the match between Great Muta and Shinsuke Nakamura at Noah The New Year 2023 left a deep impression on him and inspired his decision to pursue a career in professional wrestling.[53]