The most ancient Kōshin custom is that of staying awake one special night every sixty days. This night is called
Kōshin-Machi (庚申待 - Kōshin Waiting). The main Kōshin belief is the concept that
Three Corpses, or
Sanshi (三尸), live in every human body. The Sanshi keep track of the deeds of the person they inhabit. On the night called Kōshin-Machi, the
Sanshis leave the body and go to
Tentei (天帝), the Heavenly God, to report the deeds of that person.
Tentei then punishes bad people, making them ill, shortening their lifespans or, in extreme cases, ending their lives. Believers in Kōshin try to live without performing bad deeds, but those who believe that they have reason to fear try to stay awake during Kōshin nights, as the only way to prevent the Sanshi from reporting to
Tentei. In the
Edo period, Kōshin-Machi became more popular among commoners, leading to a proliferation of festivities and cultic activities. Many of these practices centered on the worship of specific deities. These deities were visualized in
hanging scrolls, icons, and stone carvings, many of which continue to dot the rural landscape of Japan today. One specially prominent god in the Kōshin cult was
Shōmen-Kongō (Blue-Faced
Vajra-Yakṣa), a fearsome deity with many arms. The first scriptures that established his connection with Kōshin were produced in the context of esoteric Buddhist rituals performed at the temple known as or . Another temple crucial in the early development of this cult was
Shitennō-ji. Shōmen-Kongō became Kōshin-san when people expected this deity to make the Sanshis themselves ill and prevent them from going to
Tentei. ==See also==