Namahage (生剥) is the name for demons characters that are played during a Japanese ritual of the same name.
Namahage in Japanese means blister.
Namahage is a kind of toshigami in the folklore of the Oga peninsula (Akita Prefecture in northern Honshu) that has originated as a ritual for cleansing people's souls, and for blessing the new year.
Legend has it that the Han emperor brought five demonic ogres with him to Japan a little more than two millennia ago. These oni, as they are most commonly called in Japan, stole crops and young women from Oga's villages.
The villagers decided to trick these ogres, promising to give up all their young women if the demons could build a stone staircase of one thousand stairs in a single night. If, on the other hand, the oni failed to reach the local temple to which the stairs were to be built, they would have to leave Oga never to return again.
The ogres accepted, and had reached 999 stairs when a quick-witted villager imitated a cock crowing for the arrival of down.
The surprised and dismayed oni fled, never to be seen again.
On New Year's Eve, after a ritual Shinto ceremony to purify the Namahage masks, selected local men turn into monsters for a night. Disappearing into the mountains for a time, they return shortly thereafter in full monster countenances. Roaring menacingly, they dance around bonfires, play taiko drums and visit each house in the village, shouting: "any misbehaving kids live here?" They then scare children in the houses, telling them not to be lazy or cry, though little children often do burst into tears. It is the ritual of the fathers or husbands to intercede on their family's behalf, plying the Namahage with food and saké. Then the parents will assure the Namahage that there is no bad child in their house, and give food or traditional Japanese alcoholic beverages to the demons. As the festival draws to a close, the Namahage hand out rice cakes covered with powdered black sesame seeds, another gesture of good fortune for the coming year.
An obvious purpose of the festival is to encourage young children to obey their parents and to behave, important qualities in Japan's heavily structured society. Some ethnologists and folklorists suggest it relates to a belief in deities (or spirits) coming from abroad to take away misfortune and bring blessings for the new year, while others believe it is an agricultural custom where the kami from the sacred mountains visit.