The German side spotted his potential while playing in his homeland for Cerezo Osaka, for whom he signed professional forms before graduating from high school.
He helped Cerezo gain promotion to the J-League and scored seven goals in 11 appearances in the top flight before moving to the Bundesliga in 2010 for a bargain €350,000.
In 2010/11 he scored eight goals in 18 games to earn a place in the Bundesliga Team of the Season, despite being sidelined for a lengthy spell.
And he was a key performer as Dortmund
both retained the title and lifted and German Cup in some style the following season. In addition to contributing 13 goals in the league, he scored three times in the cup.
Sir Alex Ferguson made a personal check on Kagawa's form in the cup final against Bayern Munich in Berlin, where he netted the opening goal and dazzled in a convincing 5-2 win.
Kagawa is also one the star names in what is rated by many as the best ever Japan team. His full international debut was in a Kirin Cup match against Ivory Coast in 2008 but he missed out on a place in the World Cup squad two years later.