Aobōzu

Aobōzu (青坊主, Blue Priest) are a type of Japanese yōkai (folk legend ghosts) that appear in 18th-century artist Toriyama Sekien's book Gazu Hyakki Yakō.

The aobōzu is depicted in the Gazu Hyakki Yakō as a one-eyed buddhist priest standing next to a thatched hut, however as there is no explanation of the image, the aobōzu's specific characteristics remain unknown.

It is believed that the aobōzu is the direct inspiration for the one-eyed priest hitotsume-kozō that is present in many yōkai drawings, such as Sawaki Suushi's Hyakkai-Zukan published in 1737. There is also a theory that because the kanji ao (青) in its name also means inexperienced, it was depicted as a priest who has not studied enough.