He was one of the top male Japanese biathletes from 2000 until his retirement in 2014.

Born in the city of Ojiya in the Niigata Prefecture, Isa found biathlon after graduating high school and joining the military.

[6] Isa's best relay finish in the World Cup was an 8th in Ruhpolding in 2004.

[1] After the 20 km individual race at the 2014 Olympics, Isa announced his retirement from the sport.

[8] All results are sourced from the International Biathlon Union.