 Isa akaberekerwa muguta reOjiya muNiigata Prefecture, akawana biathlon mushure mekupedza chikoro chesekondari uye kupinda muchiuto. Isa akatanga muNdebe yeNyika mumutambo wekutanga we200001 World Cup muAntholz-Anterselva, Italy. Mwaka iwoyo Isa akaita kutanga kwake paWorld Championships paWorld Championships muPokljuka. Akatorawo chikamu mumakwikwi ose eWorld Championships kubva muna 2003 kusvika muna 2009, uyezve makwikwi ose eWorld Championships kubva muna 2011 kusvika muna 2013 kuJapan. Isa akapinda mumitambo yake yekutanga yeOlympic muna 2002 uye akapindawo mumitambo yeOlympic muna 2006, 2010 na2014. Kupedza kwake kwakanakisisa pamunhu mumwe nomumwe kumaOlympics kwakauya mumakwikwi e12.5 km muna 2006, akapedza ari wechi35. Mugumo wake wakaisvonaka wokupedzisa wakasvikawo muna 2006, nzvimbo yechi 12. Mugumo wake wakanakisisa pamunhu mumwe nomumwe paWorld Championships wakauya muna 2005 muHochfilzen, uko Isa akapedza 25th mukutsvaga. Kuguma kwake kwakanakisisa muWorld Championships kwakanga kuri 11th iyo yakauya muna 2001muPokljuka. 