Higurashi no Naku Koro ni Temporada 1 Episódio 19

Shion believes the Sonozaki family is connected to the acts of demoning away people in the village, especially that of Satoshi. She imprisons Mion in the dungeon and unintentionally kills her grandmother. Shion pretends to be Mion the next day and confronts Keiichi about the previous nights encounters, to which Keiichi still denies. Later, she finally discovers the ones responsible for Satoshis disappearance.