Milk culture reaches Japan together with Buddhism, carried by people who cross the sea from China and the Korean Peninsula. Set in Japan's Tenpyo period, this animated film centers on two boys. Fukuji comes from a village that raises cows brought across the sea, and Yumihiko comes from a rice-farming Japanese village. After their village is attacked by bandits, a friendship grows between them, and that bond opens the way to cooperation and exchange across cultures.