First built as seaplane carriers of the Nisshin class during the 1930s, the two ships of the Chitose class, the Chitose and Chiyoda underwent conversations to aircraft carriers, a process that lasted nearly all of 1943. After completion, the two carriers conducted aircraft ferry runs before participating in the Battle of the Philippine Sea where they lost their entire air groups. With the destruction of potential replacements in the lead-up to the Battle of Leyte Gulf, the two Chitose class carriers sortied out one final time in order to lure away the main American carrier force, which they performed to perfection. Both are sunk with the Chitose falling to American surface ships.