Upon moving to Hinamizawa, Keiichi Maebara quickly forges friendships with the villagers, particularly Mion Sonozaki. However, a surprising revelation about Mion leads Keiichi into a precarious situation during the Cotton Drifting Festival. As Keiichi and Shion, Mion's twin sister, defy the village's customs, they face the looming threat of being spirited away. Together, they must rectify their actions before the consequences become irreversible.