Rakuten, Inc. (JSD:4755) has acquired e-reader company, Kobo, for $315 million. Based in Toronto, Kobo has produced a series of e-reader devices. Kobo is best known for working with Borders bookstores on designing a device. This past September, Kobo launched a mobile application that lets you see who is reading with you. Kobo Pulse adds social activities at a page level.

Kobo is an e-book company that has raised $50 million in funding to compete with Google Android tablets, Apple iPads, and Amazon Kindle tablets. Kobo is based in Toronto and is barely over a year old. This round was led by a leading institutional investor. Existing investors include Indigo Books & Music and Cheung Kong Holdings. These two investors put in $13 million.

Ann Arbor, Michigan based book retail company Borders Group, Inc. (NYSE:BGP) is working on an e-books initiative. Borders has partnered with Kobo Inc. to set up an online mobile store for e-books. The e-book store will be fully launched by Q2 of 2010. Kobo is a spinoff of Indigo Books & Music Inc. Kobo is planning to launch an e-book store application for the Apple App Store, BlackBerry App World, Android Market, and Palm App Catalog.

Borders is facing intense rivalry with Barnes & Noble Inc. when it comes to e-books. Barnes & Noble, Inc. (NYSE:BKS) is geared to launch Nook, an e-book reader device. Both Barnes & Noble and Borders have a bigger enemy known as Amazon.com. Amazon’s Kindle and recent exclusive deal is not helping both of the other book retail companies maintain their market share.

Below is the full press release: