Barcelona's president Josep Maria Bartomeu (L) and Rakuten's CEO Hiroshi Mikitani pose for photo with a FC Barcelona jersey during the presentation of the new main global sponsor for the FC Barcelona in Barcelona, Spain, November 16, 2016. [Photo/Xinhua]

The sponsorship deal is reported in the Spanish press to be worth slightly under 60 million euros (66 million US dollars) a year, although that could increase with variables.

Rakuten's online store currently has around 75 million users and 2016 has seen the company look to expand into European markets.

The company replaces Qatar Airways which has been Barca's sponsor for the past four years, although it has not been ruled out that Qatar Airways will maintain some form of agreement with the club.