Rika’s reference is the Oyashiro-sama from the Higurashi When They Cry manga series

Higurashi When They Cry (Japanese: ひぐらしのなく頃に, Hepburn: Higurashi no Naku Koro ni, lit. "When the Cicadas Cry"), also known simply as When They Cry prior to 2020, is a Japanese murder mystery dōjin soft visual novel series produced by 07th Expansion that comprises the first two entries of the When They Cry franchise. The series focuses on a group of young friends living in a fictional village and the strange events that occur there in 1983.

Oyashiro-sama (オヤシロ様) is the guardian deity of Hinamizawa. Although best known for his Curse, it is later revealed that Oyashiro-sama is not actually a vengeful god, but a purple-haired goddess, who would never curse people and is horrified that her name is being used in connection to such terrible things.

According to the main legend, when Onigafuchi Village was attacked by demons which arose from the Onigafuchi Swamp, Oyashiro-sama descended from the heavens to stop them and ordered them to leave the village. Since the demons had been banished from hell they had nowhere to go. The villagers took pity on the demons, and offered to let the demons live with them. Oyashiro-sama was pleased, and granted the demons human form so that they and the humans could coexist. Oyashiro-sama also stayed on the Earth to watch over them. Because of trying to bring about the unity between humans and demons, some also laud Oyashiro-sama as a god of love, marriage and matchmaking.