| Country: | Japan |
| Weight Class: | –60 kg |
| Worlds Rank: | 1 |
| Worlds Year: | 1991 |
| Regionals Type: | AS |
| Regionals Rank: | 1 |
| Regionals Year: | 1988 |
| Regionals Year2: | 1990 |
| Olympics Rank: | 3 |
| Olympics Year: | 1992 |
| Olympics Weight: | Men's 60 kg |
| Updated: | 4 June 2023 |
is a retired judoka who competed in the 60 kg division.
Koshino began learning judo with a local sports team while he was in elementary school, and became the Hokkaidō Prefecture champion for his weight class in junior-high school.[1] He placed third in the inter-highschool tournament during his senior year, and entered Tōkai University in 1985.[1] He won the Shoriki Cup twice while attending the university, and joined the Toyo Suisan corporation after graduating.[1] He won the Kodokan Cup for 4 consecutive years from 1989 to 1992 and All-Japan Weight Class Judo Championships for 3 consecutive years from 1989 to 1991,[2] and placed second in the World Judo Championships in 1989 before winning the world championships in 1991. He retired from competitive judo after finishing with a bronze medal at the 1992 Summer Olympics. He became an instructor for the International Budo University in April, 1993.