One spring, Eri, a Holstein cow, falls in love with Sawa, a Jersey newcomer. Eri idolizes Sawa and longs to be close to her, to become one with her. To refine her intense feelings for Sawa, Eri subjects herself to ascetic practices and rituals of her own making. In a world where those who do not bear children are disposed of, Eri has fallen for someone who shares the same fate.