Aki Kimiyoshi

Kimiyoshi Aki is the mother of Kimiyoshi Haruko and the grandmother of Kimiyoshi Natsumi. She's a native of Hinamizawa and also the person who triggers the events of Onisarashi-hen. Kimiyoshi Aki is a former resident of Hinamizawa, and just like the other old Hinamizawan people, she blindly belives in Oyashiro-sama. Because of her son-in law's job, she had to move from her hometown along with her family. She always looks after Natsumi and daily prays to Oyashiro-sama. After the Great Hinamizawa Disaster she starts to fear the curse of Oyashiro-sama and even drown puppies in the bathtub and hang talismans on their house in order to "protect the family from the curse". After hearing the relatives strange behavior from her mother, Natsumi in fear pushes away her grandmother who accidentaly hits her head in the desk and dies. Aki's behavior is one of the main reasons which trigger the Hinamizawa Syndrome in Natsumi and starts the tragedy in Onisarashi-hen. (Source: Higurashi No Naku Koro Ni Wiki)