About the Ketsubonkyō
The Ketsubonkyō, or Blood Bowl Sutra 血盆経, is a rather short Chinese apocryphal sutra. According to its teachings, whether by the sin of menstrual or by that of parturition blood, women are condenmed to hell for defiling the world they live in.This doctrine was proselytized from sometime in the medieval age and reached itʻs height in the Edo era.
The hell itself has been associated with various geographical locations in Japan, sometimes with bodies of water that have been colored red through volcanic activity, such as at Beppu, Osore-zan or at Tateyama. Some engis, such as the Tateyama daiengi or the Ketsubonkyō engi, rely on this sutra to localise and advertise specific ritual acts.