Here's the official Kobo announcement about their entry into the Japanese market

From the press release:

Kobo Inc., a global leader in eReading, today announced that it will launch its full eReading service in Japan on July 19. The company’s award-winning Kobo Touch™ eReader will be offered to Japanese consumers for ¥7,980 including tax (or $100 USD). Starting today July 2, the Kobo Touch eReader is now available for pre-order through Kobo’s parent company and the world’s third-largest e-commerce company, Rakuten. On July 19, Kobo will launch with a fully localized Japanese experience at http://kobo.rakuten.co.jp, with local currency, and popular Japanese content and authors.

Since its inception in December 2009, Kobo has experienced explosive growth and now boasts a catalogue of more than 2.5-million books (2.4 million available in Japan), newspapers and magazines and more than 9-million registered users worldwide. Purely focused on eReading, Kobo has driven many industry firsts including eBook gifting, and its social experience which includes Reading Life and Author Notes. Kobo has customers in 190 countries and offers localized eBookstores in Canada, the United States, the United Kingdom, Germany, the Netherlands, Australia, New Zealand, France – and now Japan.

A Local Experience for the Japanese Book Lover 
With the support of its parent-company Rakuten, Kobo will offer a robust lineup of Japanese titles, including novels, essays, business and comic books, in addition to the 2.4-million titles available in Japan. The Kobo Japanese catalogue will contain a wide assortment of titles by year end, including exclusive content only available through Kobo. Consumers can read their Kobo eBooks and graphic novels anytime, anyplace they choose with the Kobo Touch.

Selected as Wired Magazine’s 2012 Editor’s Pick for Best eReader, the Kobo Touch is equipped with EInk’s Pearl Display ePaper, which is gentle on the eyes and is easy to read even in bright sunlight. The device is lightweight at 185 grams, allowing users to read books comfortably with one hand, and has the capacity to hold approximately 1,000 books – or up to 30,000 with an SD card. The Kobo eReader travels easily, allowing booklovers to be able to enjoy books anytime they want to, on the go. Furthermore, with Wi-Fi capability, users can access the store from virtually any location. Japanese consumers can select any of the stylish Kobo colours including: Blue, Lilac, Silver, and Black. In addition, a suite of contemporary accessories have been designed for Japanese consumers including eReader covers, pocket sleeves and book lights – designed in style with the latest trends.

The Kobo Touch will use the industry standard EPUB 3.0 format, which supports layouts unique to the Japanese language including vertical text and ruby characters. Kobo has to fully adopted the ePUB 3.0 format for its Japanese eBookstore. Rakuten customers may use their Rakuten-member ID to purchase content and will earn Rakuten Super Points equivalent to 1% of their purchase amount. Rakuten Super Points can be used to purchase eBooks or redeemed across the Rakuten Ecosystem, including Rakuten’s online shopping mall Rakuten Ichiba.

Kobo’s social reading platform Reading Life™ will be supported in Japan, allowing users to gain insight into their own reading patterns. Reading Life captures the reading behavior of the user – such as how long they read, or how many pages, or their favorite time of day to read – and recognizes the achievement with Reading Life awards. These fun badges can be collected and shared with friends and fellow readers through Reading Life and Facebook™.

The eReader will be sold through Rakuten’s online shopping mall, “Rakuten Ichiba,” and “Rakuten Books”, as well as through electronics retailers. In addition, consumers can experience the easy-to-use device at dedicated “touch & try” centres that will be set up at major bookstores for people to get the full Kobo experience and ask questions to learn more about eReading and eReaders.