Watch Soap2day. It is the early 1930s and the command of the Japanese Imperial Navy determines to construct the world's biggest and most formidable battleship, Yamato. One of the admirals, Yamamoto Isoroku, disagrees. He recruits the upstart and mathematics' expert Tadashi Kai who discovers there are discrepancies between the official cost estimates and the actual figures. They soon find out that they have stumbled upon a conspiracy.