Kōsaku Aruga , was a career officer in the Imperial Japanese Navy during World War II. He commanded the battleship Yamato during its final mission, Operation Ten-Go.

Yamato (大和) was the lead ship of her class of battleships built for the Imperial Japanese Navy (IJN) shortly before World War II. She and her sister ship, Musashi, were the heaviest and most powerfully armed battleships ever constructed, displacing nearly 72,000 tonnes at full load and armed with nine 46 cm (18.1 in) Type 94 main guns, which were the largest guns ever mounted on a warship.