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.

Problem student Haru Yoshida sits next to the cold and studious Shizuku Mizutani in class. Without any other friends to turn to, both of them start to get to know each other and grow closer. Haru eventually develop feelings for Shizuku and confesses his feelings to her. Will Haru and Shizuku get their happily ever after?