The cruisers were the last class of heavy cruisers built for the Imperial Japanese Navy (IJN). In order to save design time, the ships were essentially repeats of the earlier Mogami class. Begun during World War II, only the lead ship, Ibuki, was launched, but was in the process of being converted into a light aircraft carrier when construction was suspended in 1945. She was scrapped beginning in 1946. The unnamed second ship was scrapped less than a month after being laid down in order to clear her slipway for an aircraft carrier.