Kozu took part in competitions of the Fédération Internationale de Ski from 1993 to 2010 . He ran his first World Cup race in December 1993 in Santa Caterina , which he finished classically in 44th place over 30 km. At the Nordic Junior World Ski Championships in 1994 in Breitenwang , he won silver over 30 km classic and gold with the relay. At the following Olympic Winter Games in Lillehammer , he finished 72nd place over 10 km classic and 54th place in the 25 km pursuit race. The following year he won the gold medal in the 30 km freestyle at the Winter Universiade in Candanchú . In January 1997 he got his first World Cup points with the 28th place over 10 km classic in his native Hakuba and won the 25th place over 15 km classic and the 11th place over 30 km freestyle at the Winter Universiade in Muju . His best placement at the Nordic World Ski Championships in 1997 in Trondheim was 34th in the 25 km pursuit. At the 1998 Winter Olympics in Nagano , he reached 56th place over 30 km classic, 29th place over 10 km classic and 24th place in the 25 km pursuit race. His best results at the 2002 Winter Olympics in Salt Lake City were 19th place over 15 km classic and 12th place with the relay. At the 2003 Asian Winter Games , he won silver over 15 km freestyle and gold with the relay. At the Nordic World Ski Championships in 2003 in Val di Fiemme , he achieved 32nd place over 50 km freestyle and ninth place with the relay. From the 2004/05 season to 2010, he mainly competed in the Far East Cup . He took four wins and won the overall standings in the 2006/07 season . In the 2009/10 season he finished fourth in the overall standings. His best results at the Nordic World Ski Championships 2007 in Sapporo were 39th place over 15 km freestyle and 14th place with the relay. In November 2009 he completed his last World Cup race in Beitostølen . He achieved 16th place over 15 km freestyle and thus achieved his best placement in an individual World Cup race.
Kozu was Japanese champion over 10 km classic in 2001 and in 2004 over 15 km freestyle.
Japan
Snow farm