Yagomori refers to an ancient tradition of young men and women gathering at Hachiman Shrine to drink, feast, make merry, and spend the night.
Yagomori occurs twice a year. The first occurrence, called Kami Watashi (Flight of the Gods), is held on the 29th day of the 9th month of the Japanese lunisolar calendar—the night before all gods across Japan gather at the Izumo Grand Shrine in Shimane Prefecture. In place of the otherwise occupied gods, participants of Yagomori are said to be protecting the village during the night while the deities are away.
The second occurrence is one month later, on the 30th day of the 10th month of the Japanese lunisolar calendar, and is called Kami Modoshi (Return of the Gods). It is on this day that the gods are said to return from Izumo Grand Shrine, and this night occurs much in the same manner as that from a month prior, though this time the event is held to welcome the gods back home.
Izumo Grand Shrine is also known as the shrine of fate and intertwined destinies—as such, many a young man and woman have had their fates intertwined on these nights of Yagomori. The tradition of Yagomori continues to this day.