Momodayu (also called Hyakudayu) is a deity in a folk belief.
Its origin is not clear. The deity was worshipped by puppet players and yujo (a prostitute) and is enshrined as Massha (small shrine belonging to the main shrine) particularly in regions of west Japan. It is generally regarded as a male god, which is worshiped with many curved wooden statues. OE no Masafusa wrote in "Kugutsushiki" (a document about entertainers) that puppet players worshipped one hundred gods. In "Ryojin Hisho" (folk song collection) and "Yujo Ki" (a document about prostitutes), Momodayu is described as a god worshipped by yujo. It is also beloved in as Doso-shin (traveler's guardian deity) or a god that wards off smallpox.
The first Massha (small shrine belonging to the main shrine) of Kitano Tenmangu Shrine, Shiradayu Shrine is often confused with Momodayu, because similar kanji and sounds are used. Shiradayu is enshrined in Tenmangu Shrines all over the county.. Some suggest that the Tenmangu Shrines are dedicated to Michizane SUGAWARA's servant, Haruhiko WATARAI who was a priest of Geku Shrine (the Outer Shrine of Ise-jingu Shrine).