Question and answer sites have for a decade been one of the most popular user-contributed services on the Web — and Japan is no exception. On the traditional Web, the market has been occupied by a few big players, but the recent popularity of smartphones has attracted new startups to the mobile Web field.

Q&A services are not a new thing in Japan. OKWave began its Q&A service in 1999 and its content is syndicated to many other sites. For example, portal site goo hosts Q&As from OKWave under its Oshiete! goo (Teach Me! goo) section.

Hatena started Jinriki Kensaku Hatena (Human Search Hatena) in 2001. The site first gained popularity among tech-savvy users, which Hatena consolidated by targeting a nerd-centric community with other popular services such as blogs and social bookmarks.