Tokyo-based Rakuten Inc. will invest US$100 million into the website, which launched in 2010 but has experienced a surge in popularity this year.
Pinterest is a platform that allows users share photos with their friends on a pinboard-style webpage layout. The site also provides a marketplace for its users to sell products.
Rakuten says the investment will allow it to access synergies between Pinterest and its own e-commerce model, which includes websites Buy.com and Play.com.
The company also hopes to expand Pinterest into Japan and its 17 other global markets.
Rakuten acquired all of Toronto-based Kobo for US$315 million in January, including the 51-per cent stake owned by Indigo Books & Music Inc.