ClassNK

The Society traces its origins to the Teikoku Kaiji Kyokai (Imperial Marine Association), founded in Tokyo in November 1899. The first ship to receive its class certificate was the Kwanan Maru in 1920, and under the Ship Safety Law of 1934 it officially became Japan's ship classification society. It was relaunched under its current name, Nippon Kaiji Kyokai, in 1946.

ClassNK opened offices in London and New York in 1962 and was a founding member of the International Association of Classification Societies (IACS) in 1968, which it has chaired four times. In 2012 it became the first class society to have more than 200 million gross tons on its register. Since 1 April 2011 it has been a general incorporated foundation under Japanese law, operating as an independent, not-for-profit third party.