Onda Matsuri - Japanese Fertility/Rice-Planting Festival おんだ祭 お尻たたき
Onda Matsuri is a Japanese Fertility Rice-planting Festival at Asuka Niimasu Shrine in Asuka Mura where they act out sowing rice then a sex act between a long-nose tengu goblin and his wife (both played by men).
Afterwards, masked men go out an administer beatings with bamboo canes to bring good luck