Mei Yamaguchi

Early life Yamaguchi was born in Tokyo, Japan on , and grew up with a sister and a little brother. While living in Los Angeles, California, she studied some of her elementary school years before returning to Japan following her mother's unexpected death. In junior high she played softball, and during college she started training in Brazilian Jiu-Jitsu. After returning to Japan, she joined Butoku Kai. She currently serves as the leader of the Morishita branch.

In 2005, Yamaguchi entered into the Max Jiu-Jitsu Academy.

Yamguchi won her next fight in Smackgirl, defeating Saori Ishioka with a kneebar, forcing Ishioka to tap in the second round in the semi-finals at Smackgirl-F 2007: The Next Cinderella Tournament 2007 2nd Stage on .

On at Smackgirl 2007: Queens' Hottest Summer, Yamaguchi defeated Emi Tomimatsu by split decision, winning the final of the Next Cinderella Tournament 2007 in the lightweight division.

In her last fight with the promotion Smackgirl and her fourth professional match, Yamaguchi was defeated via split decision by Emi Fujino on at Smackgirl 7th Anniversary: Starting Over.

Her next bout would be at the first event for the promotion Valkyrie, Valkyrie 01, where she lost by unanimous decision against women's MMA legend Yuka Tsuji on . It was just the fourth time that Tsuji had been taken to a decision.

Yamaguchi rebounded by winning her next two bouts in the inaugural Valkyrie women's featherweight tournament. The first was a unanimous decision win over Emi Fujino on at Valkyrie 02 in a rematch of their 2007 bout. The second tournament bout was against Kyoko Takabayashi, whom Yamaguchi was able to defeat with a close split decision at Cage Force & Valkyrie on , winning the tournament in the process and earning the right to face Yuka Tsuji for Valkyrie's Featherweight championship.

At Valkyrie 04, in her second match against Tsuji, Yamaguchi was once again the underdog, but she managed to defeat Tsuji with a rear naked choke in only 76 seconds. This was the first time that Tsuji was defeated by a fellow Japanese fighter and only the second time that she had been defeated in her MMA career. Yamaguchi became Valkyrie's Featherweight Champion in what is considered one of the biggest upsets in the history of women's mixed martial arts.

On , Yamaguchi faced Kyoko Takabayashi in a rematch of the 2009 featherweight tournament final and Yamaguchi's first defense of Valkyrie's featherweight title. Yamaguchi barely retained with a contentious majority draw in which the dissenting judge scored the fight in favor of Takabayashi at Valkyrie 08.

Yamaguchi faced "Windy" Tomomi Sunaba at Pancrase Impressive Tour 3 on . She defeated Sunaba by majority decision.

Yamaguchi next faced Akiko Naito at Pancrase Impressive Tour 4 on . She defeated Naito by armbar submission in the first round.

Jewels Yamaguchi faced Seo Hee Ham in a Jewels vs. Valkyrie match at Jewels 15th Ring on . She was defeated by unanimous decision.

Yamaguchi faced Mika Nagano at Jewels 17th Ring on . She won the fight by split decision.

Yamaguchi fought outside Japan for the first time in her MMA career when she faced Katja Kankaanpää at Botnia Punishment 11 on in Finland. She was defeated by unanimous decision.

On , Yamaguchi faced Emi Tomimatsu in a rematch at Jewels 20th Ring. She defeated Tomimatsu by unanimous decision.

Yamaguchi next faced Megumi Fujii at Vale Tudo Japan 2012 on . She was defeated by unanimous decision.

On , Yamaguchi faced Seo Ye Jung at Jewels 24th Ring. She defeated Jung by submission due to an armbar in the first round.

PXC In her second fight outside Japan, Yamaguchi faced Patricia Vidonic at Pacific Xtreme Combat 40 on in Guam. She was defeated by split decision.

In her sophomore bout in PXC, Yamaguchi faced Gina Iniong at PXC 43 on March 29, 2014. She lost the bout via split decision.

Deep Jewels After Jewels brand was merged into Deep, Yamaguchi faced Yukiko Seki at Deep Jewels 4 on May 18, 2014. She won the bout via first-round technical submission.

In her sophomore bout in the promotion, Yamaguchi faced Ayaka Hamasaki at Deep - Dream Impact 2014: Omisoka Special on December 31, 2014. She lost the bout via unanimous decision.

She was then scheduled to face Ayaka Miura at Deep Jewels 7 on February 20, 2015. However, Miura withdrew from the bout and was replaced by Miyoko Kusaka. Yamaguchi won the bout via first-minute knockout.

Deep Jewels Featherweight GP and championship In May 2015, Yamaguchi entered into a single-day, four-woman featherweight grand prix which would crown the vacant Jewels Atomweight champion.

She claimed the title by first defeating Mina Kurobe and then Satomi Takano.

Return attempt to PXC Yamaguchi was scheduled to face Tessa Simpson at PXC 52 on March 18, 2016. However, Yamaguchi withdrew from the bout citing an injury and was replaced by her latest opponent Satomi Takano.

ONE Championship and return to strawweight In late March 2016, it was announced that Yamaguchi had signed with the ONE Championship, and would debut against Angela Lee for the inaugural ONE Women's Atomweight Championship at ONE Championship: Ascent to Power on May 6, 2016. She lost the bout via unanimous decision.

Post-title shot reign In her sophomore bout in the promotion, Yamaguchi faced Istela Nunes at ONE Championship: Heroes of the World on August 13, 2016. Yamaguchi lost the bout via split decision.

Return to contention and title rematch Yamaguchi then faced Jenny Huang at ONE Championship: Light of a Nation on June 30, 2017. She won the bout via second-round submission.

She was then scheduled to challenge Angela Lee in a rematch for the ONE Women's Atomweight Championship at ONE Championship: Immortal Pursuit on November 24, 2017. However, Lee was involved in a car accident, the bout was scrapped and Yamaguchi faced Gina Iniong instead. She won the bout via unanimous decision.

The title shot against Lee was then rebooked to take place at ONE Championship: Unstoppable Dreams on May 18, 2018. Despite knocking Lee down multiple times during the bout, Yamaguchi failed to capture the belt in her second attempt, losing via unanimous decision.

Winning streak After the title shot loss, Yamaguchi faced Jomary Torres at ONE Championship: Destiny of Champions on December 7, 2018. She won the bout via unanimous decision.

She was then scheduled to face Bo Meng at ONE Championship: Call to Greatness on February 22, 2019. However, the bout was scrapped as Meng withdrew from the bout due to an injury.

She then faced Kseniya Lachkova at ONE Championship: A New Era on March 31, 2019. She won the bout via third-round submission.

Meng bout was then rebooked to take place at ONE Championship: Enter the Dragon on May 17, 2019. However Meng bowed out from the bout again due to an injury and was replaced by Laura Balin. Yamaguchi won the bout via first-round submission.

She then faced Jenny Huang in a rematch at ONE Championship: Century on October 13, 2019. She won the bout via unanimous decision.

Losing streak and departure from ONE The bout with Bo Meng was rebooked for the third time to take place at ONE Championship: King of the Jungle on February 28, 2020. Meng the withdrew from the bout once again and was replaced by Denice Zamboanga. Yamaguchi lost the bout via unanimous decision.

Yamaguchi faced Julie Mezabarba as part of an alternate bout for the Atomweight World Grand-Prix at ONE Championship: Empower on September 3, 2021. She lost the bout via unanimous decision.

Yamaguchi faced Jihin Radzuan at ONE: Bad Blood on February 11, 2022, as a late notice replacement for Jenelyn Olsim. She lost the bout via unanimous decision.

Post ONE In order to finish her career in her native Japan, she was granted an early release from ONE and subsequently signed with Rizin Fighting Federation. She dropped to super atomweight division and made her promotional debut against Kanna Asakura on April 29, 2023, at Rizin Landmark 5. She lost the bout via unanimous decision.

In her next bout, Mei faced Sayako Fujita on December 24, 2023 at Pancrase 340, losing the bout via split decision.

Submission grappling and shoot boxing career Yamaguchi tried her hand in submission grappling, first in the Abu Dhabi Combat Club Japan Trial final qualifier in the under-55 kg class, where she was defeated by points by Yasuko Mogi on . In her second and final submission grappling match, she was once again defeated by points; this time by women's MMA star Miku Matsumoto at DEEP X03 on .

Yamaguchi has had a more successful run in shoot boxing. She began competing on , in the shoot boxing tournament Girls S-Cup 2009, where she defeated by decision South Korean female Muay thai kickboxer Su Jeong Lim and fellow mixed martial artist and karateka Madoka Okada before losing against female shoot boxing rising star Rena Kubota in the tournament final. Yamaguchi won her next two bouts by decision. She participated in the shoot boxing Girls S-Cup 2010, defeating Samanta van Dole by technical submission (standing guillotine choke) and losing against Ai Takahashi by unanimous decision after an extra round.

On , Yamaguchi entered the 2011 Shoot Boxing Girls S-Cup tournament. She faced Mina in the opening round and was defeated by majority decision.

Yamaguchi entered the 2012 Shoot Boxing Girls S-Cup on . She defeated Namtarn Por Munagpetch and Lorena Klijn to advance to the final round, but lost to Rena Kubota via unanimous decision in the tournament final.

Yamaguchi faced Lorena Klijn in a rematch at Shoot Boxing 2013: Act.3 on . She was defeated by unanimous decision.

Yamaguchi was scheduled to compete against Du Peiling at the 2013 Shoot Boxing Girls S-Cup Japan Midsummer Festival on . However, Peiling suffered an injury and Yamaguchi instead faced Chihiro Kira. She defeated Kira by unanimous decision.

Yamaguchi faced Danielle Kelly in a grappling match at ONE: X on March 26, 2022. They grappled to a draw after 12 minutes after neither could find the submission.

Yamaguchi competed in a superfight against Hakuri Ishiguro at Quintet 4 on September 10, 2023. She was submitted with a kneebar.

Championships and accomplishments

Mixed martial arts Jewels Deep Jewels Atomweight Champion (one time; former) Smackgirl Smackgirl-F The Next Cinderella Tournament 2007 Lightweight winner Greatest Common Multiple Valkyrie Featherweight Tournament winner Valkyrie Featherweight Champion (one time; last) MMA Junkie 2016 #4 Ranked Fight of the Year 2016 May Fight of the Month vs. Angela Lee

Shoot boxing 2009 Shoot Boxing Girls S-Cup runner-up 2012 Shoot Boxing Girls S-Cup runner-up

Mixed martial arts record Loss

Sayako Fujita Decision (split) Pancrase 340

Yokohama, Japan Loss

Kanna Asakura Decision (unanimous) Rizin Landmark 5

Tokyo, Japan Loss

Jihin Radzuan Decision (unanimous) ONE: Bad Blood

Kallang, Singapore Loss

Julie Mezabarba Decision (unanimous) ONE: Empower

Kallang, Singapore Loss

Denice Zamboanga Decision (unanimous) ONE: King of the Jungle

Kallang, Singapore Win

Jenny Huang Decision (unanimous) ONE: Century Part 2 |

Tokyo, Japan Win

Laura Balin Submission (Armbar) ONE: Enter the Dragon |

Kallang, Singapore Win

Kseniya Lachkova Submission (Armbar) ONE: A New Era |

Tokyo, Japan Win

Jomary Torres Decision (unanimous) ONE: Destiny of Champions

Kuala Lumpur, Malaysia Loss

Angela Lee Decision (unanimous) ONE: Unstoppable Dreams

Kallang, Singapore Win

Gina Iniong Decision (unanimous) ONE: Immortal Pursuit

Kallang, Singapore Win

Jenny Huang Submission (rear-naked choke) ONE: Light of a Nation

Yangon, Myanmar Loss

Istela Nunes Decision (split) ONE: Heroes of the World

Macau, China Loss

Angela Lee Decision (unanimous) ONE: Ascent to Power

Kallang, Singapore Win

Satomi Takano TKO (punches)

Win

Mina Kurobe Decision (unanimous)

Win

Miyoko Kusaka KO (knee to the body) Deep Jewels 7

Tokyo, Japan Loss

Ayaka Hamasaki Decision (unanimous) Deep - Dream Impact 2014: Omisoka Special

Saitama, Japan Win

Yukiko Seki Technical Submission (rear-naked choke) Deep-Jewels 4

Tokyo, Japan Loss

Gina Iniong Decision (split) Pacific Xtreme Combat 43

National Capital Region, Philippines Loss

Patricia Vidonic Decision (split) Pacific Xtreme Combat 40

Mangilao, Guam, United States Win

Seo Ye Jung Submission (armbar) Jewels 24th Ring

Kabukicho, Tokyo, Japan Loss

Megumi Fujii Decision (unanimous) Vale Tudo Japan 2012

Shibuya, Tokyo, Japan Win

Emi Tomimatsu Decision (unanimous) Jewels 20th Ring

Koto, Tokyo, Japan Loss

Katja Kankaanpää Decision (unanimous) Botnia Punishment 11: Kankaanpää vs. Yamaguchi

Seinäjoki, Finland Win

Mika Nagano Decision (split) Jewels 17th Ring

Kabukicho, Tokyo, Japan Loss

Seo Hee Ham Decision (unanimous) Jewels 15th Ring

Kabukicho, Tokyo, Japan Win

Akiko Naito Submission (armbar) Pancrase: Impressive Tour 4

Koto, Tokyo, Japan Win

Tomomi Sunaba Decision (majority) Pancrase: Impressive Tour 3

Koto, Tokyo, Japan Draw

Kyoko Takabayashi Draw (majority) Valkyrie 08

Koto, Tokyo, Japan Win

Yuka Tsuji Submission (rear-naked choke) Valkyrie 04

Koto, Tokyo, Japan Win

Kyoko Takabayashi Decision (split) Cage Force & Valkyrie

Koto, Tokyo, Japan Win

Emi Fujino Decision (unanimous) Valkyrie 02

Koto, Tokyo, Japan Loss

Yuka Tsuji Decision (unanimous) Valkyrie 01

Koto, Tokyo, Japan Loss

Emi Fujino Decision (split) Smackgirl 7th Anniversary: Starting Over

Bunkyo, Tokyo, Japan Win

Emi Tomimatsu Decision (split) Smackgirl 2007: Queens' Hottest Summer

Bunkyo, Tokyo, Japan Win

Saori Ishioka Submission (kneebar) Smackgirl-F 2007: The Next Cinderella 2007 2nd Stage

Bunkyo, Tokyo, Japan Win

Anna Saito Submission (rear-naked choke) Smackgirl-F 2007: The Next Cinderella Tournament 2007 First Stage

Kabukicho, Tokyo, Japan Submission grappling record Draw Danielle Kelly ONE: X Kallang, Singapore Decision 1 12:00 0-2-1 Loss Miku Matsumoto DEEP X03 Tokyo, Japan Points (4-10) 2 4:00 0-2-0 Loss Yasuko Mogi Abu Dhabi Combat Club Japan Trial final qualifier Tokyo, Japan Points (2-6) N/A N/A 0-1-0 Women under-55 kg class - 1st round

Shoot boxing record