Japan international midfielder Shinji Kagawa has extended his contract with Borussia Dortmund until 2020, the German club said on Friday.

"We're very pleased that Shinji will play for us for another three seasons," Dortmund sporting director Michael Zorc said as the club arrived in Tokyo on Friday on its pre-season tour.

"Shinji identifies with our club, the city and the fans. He's also an important role model for our young team."

The 28-year-old has scored 54 goals in 185 appearances for Dortmund over two spells, winning the Bundesliga twice in a row following his arrival in 2010.

He rejoined the club in 2014 after a couple of seasons with Manchester United.