is a Japanese competitive

swimmer Swimming is an individual or team racing sport that requires the use of one's entire body to move through water. The sport takes place in pools or open water (e.g., in a sea or lake). Competitive swimming is one of the most popular Olympic ...

and

breaststroke Breaststroke is a swimming style in which the swimmer is on their chest and the torso does not rotate. It is the most popular recreational style due to the swimmer's head being out of the water a large portion of the time, and that it can be s ...

specialist. He won the 100-meter event at the

2013 Summer Universiade The 2013 Summer Universiade, officially known as the XXVII Summer Universiade (russian: XXVII Летняя Универсиада), was held in the city of Kazan, Russia, the most northerly city ever to host a Summer Universiade. Over 10,400 un ...

, 2013 East Asian Games, and the

2014 Pan Pacific Swimming Championships The 2014 Pan Pacific Swimming Championships, also known as the 2014 Hancock Prospecting Pan Pacific Swimming Championships, a long course (50 m) event, was held in Gold Coast, Queensland, Australia, from 21 to 25 August 2014. Qualifying cr ...

. He hold the Asian record in this event, set in February 2014. Since 2010 Koseki studied at the

Nippon Sport Science University , abbreviated as , is a private university in Setagaya, Tokyo and Aoba-ku, Yokohama. The precursor of the school was founded in 1893, and it was chartered as a university in 1949. The school is known for the many famous athletes among its alumni. ...

, where he first specialized in the freestyle, and only later changed to breaststroke, motivated by

Kosuke Kitajima is a Japanese retired breaststroke swimmer. He won gold medals at the men's 100 m and 200 m breaststroke events at the 2004 Summer Olympics, and the 2008 Summer Olympics – becoming the first and only swimmer to sweep the breaststroke even ...

References

1992 births Living people Japanese male breaststroke swimmers Asian Games medalists in swimming Swimmers at the 2014 Asian Games Swimmers at the 2018 Asian Games Asian Games gold medalists for Japan Asian Games silver medalists for Japan Asian Games bronze medalists for Japan Swimmers at the 2016 Summer Olympics Olympic swimmers of Japan Medalists at the 2014 Asian Games Medalists at the 2018 Asian Games World Aquatics Championships medalists in swimming Universiade medalists in swimming Universiade gold medalists for Japan Universiade silver medalists for Japan Medalists at the 2013 Summer Universiade 21st-century Japanese people {{Japan-swimming-bio-stub