 Iwabuchi akatanga basa rake repasi rose muna 2008 paakasarudzwa muchikwata chenyika cheJapan U-17 aine makore gumi nemashanu, uye akatora chikamu mu2008 U-17 World CupmuNew Zealand. Chikwata chakakundwa mumakwikwi ekupedzisira asi iye akapihwa MVP yemutambo adidas Golden Ball. Murairidzi wechikwata cheFrance akamurumbidza senyeredzi yemberi yenhabvu yevakadzi. Iwabuchi akapiwawo mubayiro weAsia Young Footballer of the Year neAsian Football Confederation muna 2008. Akabatana nechikwata chenyika cheJapan kuEast Asian Football Championship, yakaitwa kutanga kwa2010, uye akatanga mumutambo wakanangana neChina. Akatora chibodzwa chake chekutanga achipesana nechikwata chenyika cheChinese Taipei mumakwikwi akafanana. Muna 2011, akatamba pa2011 World Cup uye Japan yakahwina mukombe. Akatamba semutambi akatsiva mumutambo wokupedzisira neUnited States. Akatambawo 2012 Summer Olympics uye 2015 World Cup. Japan yakawana nzvimbo yechipiri mumakwikwi ose ari maviri. Muna 2018, pa2018 Asia Cup, akatamba nguva yakazara mumitambo yese uye akarova zvibodzwa zviviri. Japan yakakunda mukombe uye iye akasarudzwa MVP mibairo. Akatamba mitambo 61 uye akarova zvibodzwa 20 zveJapan. 