ANN: It's Yokohama, 1963. Each morning a girl on a high hilltop hoists signal flags to greet the ships in the bay below. She is Umi Matsuzaka, a sensible, responsible girl, who disapproves of the antics of the boys in her school. She especially disapproves of their bold ringleader, Shun, when he inadvertently embarrasses her. Nonetheless, Umi is drawn into the boys' campaign to preserve a dilapidated club house and finds herself warming to Shun, sensing a strength of character like her own.