Kim Mijinsu

is a synchronized swimming coach in Japan. Born to a Korean family in Japan, she participated in Japanese domestic synchronized swimming competitions under the name Mizuho Kōchi, and represented South Korea in international competitions under the name Kim Mijinsu, most notably in the women's solo and women's duet competitions at the . After her retirement from the South Korean national team, she married and began using her current name.

Early life Katayama is a third-generation Korean resident of Japan and was born in Izumiōtsu, Osaka Prefecture. Her only given name since birth has been the Japanese given name Mizuho; her legal birth surname was Kim, while she used the Japanese name Mizuho Kōchi as a pass name. She went on to attend in Takaishi. She entered the Osaka University of Health and Sport Sciences in 1987. She competed under the name Kim Mijinsu, where "Mijinsu" is the Korean pronunciation of the characters she used at the time for her given name Mizuho. She again represented South Korea in the duet routine at the 1991 World Aquatics Championships with partner Choe Jeong-yun, and placed thirteenth. She placed first in the duet routine at the 1991 with partner Chiaki Yamamura .

After her wedding in 1993 to a Japanese man from Hiroshima, she used the married name Mizuho Katayama. She moved to Hiroshima, and became an instructor at the Hiroshima Synchronized Swimming Club, a board member of the Hiroshima Prefectural Swimming Federation, and a synchronized swimming referee for the National Sports Festival of Japan. She was the coach for the Japanese team at the 2003 and 2004 Swiss Open Synchronized Swimming organized by . She was later the head coach for Japan's junior synchronized swimming team at the Asia Swimming Federation's 2007 Asian Age Group Championships in Jakarta, Indonesia, and the 2008 FINA World Junior Synchronised Swimming Championships in Saint Petersburg, Russia. She was promoted to head coach of Japan's national synchronized swimming team for the 2009 World Aquatics Championships in Rome, Italy. At the synchronized swimming school Artistic Swimming Hiroshima , she was the coach of future Olympian from 2016 to 2022.