Musashi has been defeated and Yokosuka Girls Marine High School girls are safe back home. However, Herakaze sustained critical damage during its final battle with Musashi and may not be able to sail again. There are rumors that the Harekaze-class will be dissolved due to it lacking a ship. Other classes are trying to scout members from the Harekazes crew, which is making the situation even more uncertain. The solution to this urgent problem might lie in the sealed orders that Kouko Nosa, secretary of the Harekaze, has to deliver to its crewmembers. But time is running out.