The Japanese aircraft carrier Taiyo ("Big Eagle") was the lead ship of her class of three escort carriers. She was originally built as Kasuga Maru , the last of three Nitta Maru class of passenger-cargo liners built in Japan during the late 1930s for NYK Line. The ship was requisitioned by the Imperial Japanese Navy (IJN) in early 1941 and was converted into an escort carrier. Taiyo was initially used to transport aircraft to distant air bases and for training, but was later used to escort convoys of merchant ships between Japan and Singapore. The ship was torpedoed twice by American submarines with negligible to moderate damage before she was sunk in mid-1944 with heavy loss of life.