Mei Yamaguchi has 16 losses against 15 opponents on her MMA record. For a list of Yamaguchi's best fights, refer to "Best fights of Mei Yamaguchi".
On December 24, 2023 Mei Yamaguchi faced off against Sayako Fujita in a atomweight bout at age 40. She was coming in with a record of 21-16-1 (10). Yamaguchi lost the fight via 3-round split decision.
On April 29, 2023 Mei Yamaguchi faced off against Kanna Asakura in a atomweight bout at age 40. She was coming in with a record of 21-15-1 (10). Yamaguchi lost the fight via 3-round unanimous decision.
On February 11, 2022 Mei Yamaguchi faced off against Jihin Radzuan in a atomweight bout at age 39. She was coming in with a record of 21-14-1 (10). Yamaguchi lost the fight via 3-round unanimous decision.
On September 3, 2021 Mei Yamaguchi faced off against Julie Mezabarba in a atomweight bout at age 38. She was coming in with a record of 21-13-1 (10). Yamaguchi lost the fight via 3-round unanimous decision.
On February 28, 2020 Mei Yamaguchi faced off against Denice Zamboanga in a strawweight bout at age 37. She was coming in with a record of 21-12-1 (10). Yamaguchi lost the fight via 3-round unanimous decision.
On May 18, 2018 Mei Yamaguchi fought Angela Lee in a atomweight title fight for Lee's ONE Women's Championship title. Yamaguchi was 35 years old and with a record of 17-11-1 (8), and Lee was 21 years old and with a record of 8-0 (7). Yamaguchi lost the fight via 5-round unanimous decision.
On August 13, 2016 Mei Yamaguchi faced off against Istela Nunes in a atomweight bout at age 33. She was coming in with a record of 15-10-1 (7). Yamaguchi lost the fight via 3-round split decision.
On May 6, 2016 Mei Yamaguchi fought Angela Lee in a atomweight title fight for Lee's ONE Women's Championship title. Yamaguchi was 33 years old and with a record of 15-9-1 (7), and Lee was 19 years old and with a record of 5-0 (5). Yamaguchi lost the fight via 5-round unanimous decision.
On December 31, 2014 Mei Yamaguchi faced off against Ayaka Hamasaki in a atomweight bout at age 31. She was coming in with a record of 12-8-1 (5). Yamaguchi lost the fight via 2-round unanimous decision.
On March 29, 2014 Mei Yamaguchi faced off against Gina Iniong in a featherweight bout at age 31. She was coming in with a record of 11-7-1 (5). Yamaguchi lost the fight via 3-round split decision.
On October 25, 2013 Mei Yamaguchi faced off against Patricia Vidonic in a featherweight bout at age 30. She was coming in with a record of 11-6-1 (5). Yamaguchi lost the fight via 3-round split decision.
On December 24, 2012 Mei Yamaguchi faced off against Megumi Fujii in a featherweight bout at age 29. She was coming in with a record of 10-5-1 (4). Yamaguchi lost the fight via 2-round unanimous decision.
On March 23, 2012 Mei Yamaguchi faced off against Katja Kankaanpää in a featherweight bout at age 29. She was coming in with a record of 9-4-1 (4). Yamaguchi lost the fight via 3-round unanimous decision.
On July 9, 2011 Mei Yamaguchi faced off against Seo Hee Ham in a featherweight bout at age 28. She was coming in with a record of 8-3-1 (4), and Ham was 24 years old and with a record of 9-4 (1). Yamaguchi lost the fight via 2-round unanimous decision.
On November 8, 2008 Mei Yamaguchi faced off against Yuka Tsuji in a lightweight bout at age 25. She was coming in with a record of 3-2 (2). Yamaguchi lost the fight via 3-round unanimous decision.
On December 26, 2007 Mei Yamaguchi faced off against Emi Fujino in a lightweight bout at age 24. She was coming in with a record of 3-1 (2). Yamaguchi lost the fight via 2-round split decision.