DEEP Jewels World Champion Mei Yamaguchi was born in Tokyo, and she started learning karate at the age of 6 because she wanted to be like action star Jackie Chan. She went to school in Los Angeles, and grew up dividing her time between Japan and the United States. After she tragically lost her mother to illness, Yamaguchi found comfort in martial arts and threw herself into training.
After moving back to Japan, she made her professional mixed martial arts debut in 2007, and won a four-woman tournament two years later to become the Valkyrie Featherweight Champion. In 2015, Yamaguchi claimed the second championship of her veteran career by defeating three tough opponents to win the DEEP Jewels Featherweight Grand Prix and the belt. Following great success in Japan, she finally made her ONE Championship debut in May 2016 with a shot at the inaugural ONE Women’s Atomweight World Championship, and she went five action-packed rounds with Angela Lee.
Despite a valiant effort that was undoubtedly the toughest test of Lee’s career to date, Yamaguchi ultimately lost by unanimous decision in a bout that deservedly won several Bout of the Year awards. After taking the time to correct all the mistakes she made the first time, the veteran Japanese warrior bounced back with huge wins over top contenders Jenny Huang and Gina Iniong to earn another shot at the coveted belt, and she continues her quest for the World Title today.