Akira Tachibana is a 17-year-old high school student. She was once a promising athlete, but an injury has prevented her from taking part in track and field. One day, Akira Tachibana goes to a family restaurant and the manager talks to her in a tender voice. This makes Akira Tachibana begin working part-time at the restaurant. The manager is 45-year-old Masami Kondo and he is divorced with a child. Akira Tachibana falls in love with him.
Akari is a first grade high school student. She is positive, realistic and outgoing with romance. Akari though is not good at expressing her feelings. She become friends with Yuna, who attends the same high school. Yuna has a hard time talking with strangers and she is passive with romance. She has never been in love, but she dreams of having a romance like those drawn in manga. Even though Akari and Yuna have totally different personalities, they are now good friends. Yuna gets attracted to Rio who is Akari’s stepbrother and attends the same high school. Akari becomes attracted to Kazuomi, who is Yuna’s childhood friend and attends the same high school.
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.
