Yokohama Xebec is a marching band of a port city, Yokohama. The band goes by the philosophy, 'One for all. All for one.' Band captain Mari, is determined to win this year's national competition. But when the band's lead trumpeter, Tadanobu, announces his decision to leave the band after the season to pursue music as a professional, it causes a stir among the members. Tadanobu's family is currently hosting his aunt and his cousin, Yukie and Yosuke, who have fled the tsunami stricken Fukushima. This movie features the bond between the people of Iwabune and the members of Yokohama's marching band. As the national competition approaches, the young people of two port towns come together through music and take an unexpected action...