a four-year deal.
The 25-year-old Japan international midfielder
leaves Manchester United having failed to impress
new manager Louis van Gaal.
Kagawa moved to Old Trafford in the summer of
2012 having spent two years in Germany where he
collected back-to-back Bundesliga titles with
Dortmund.
He also picked up a Premier League winners' medal
at Old Trafford during Sir Alex Ferguson's final
season.
However, his only appearance for United this
campaign was a 20-minute spell during their
shambolic 4-0 Capital One Cup defeat to Milton
Keynes Dons earlier this week.
Kagawa made 57 appearances for United, scoring six
goals that included a hat-trick against Norwich.
He told Dortmund's official website: "I wanted to
realise my Premier League dream but now I'm
happy to be back in Dortmund.
"This great team, a unique environment and
Dortmund is like a family. I am proud they have
never forgotten me and I can belong again."
Dortmund's sporting director Michael Zorc added:
"The possibility of signing Shinji from Manchester
United only arose for the first time in the last few
days.
"Naturally we decided to add his enormous quality
to our squad once again."
Keep up with all the latest transfer news and
rumours on Deadline Day - coverage
throughout the day on Sky Sports News HQ
until the 11pm deadline with guests including
Jamie Carragher, Jamie Redknapp, Rene
Meulensteen, Christian Purslow, Guillem
Balague and Niall Quinn.
Sent from my BlackBerry® wireless handheld from Glo Mobile.