It is operated by Voyage Marketing Co. At launch, the service's name was in rōmaji, but has since been stylized in katakana.

[1] The "kotobank" service was launched on April 23, 2009, under the management of The Asahi Shimbun and EC Navi Inc.[2] At launch, it claimed to cover a total of 430,000 entries from 44 dictionaries and encyclopedias, the core of which were provided by Kodansha, Shogakukan, and Asahi Shimbun Publishing.

[7] When the service was launched in 2009, The Asahi Shimbun and other operators pointed out the unreliability of information on the Internet and stated, "We aim to be the largest free glossary site in Japan with high reliability, quality and searchability of information.

[2] We will build a highly reliable website," said Hiromi Onishi, head of the Digital Media Division at The Asahi Shimbun.

[1] The National Diet Library's Collections and Bibliography Department states that items listed in the Kotobank may be used as a reference when establishing new ordinary subjects in the National Diet Library's Subject Headings List if they "exist in book form, such as the Encyclopedia MyPedia, or are successors to it," and "the explanations of words and phrases are general rather than intended for specific users.