was an aircraft carrier built for the Imperial Japanese Navy (IJN) and was named after the former Kaga Province in present-day Ishikawa Prefecture. Originally intended to be one of two s, "Kaga" was converted under the terms of the Washington Naval Treaty to an aircraft carrier as the replacement for the battlecruiser , which had been irreparably damaged during the 1923 Great Kantō earthquake. "Kaga" was rebuilt in 1933–1935, increasing her top speed, improving her exhaust systems, and adapting her flight decks to more modern, heavier aircraft.