Aobōzu

Sources do not provide a single origin myth. Across regions the aobōzu is variably explained as (a) an animistic/local kami manifestation (in Yamaguchi as a form taken by Yama-no-Kami), (b) an animal (weasel or tanuki) in priestly disguise (Kaneyama/Fukushima, parts of Gifu and Hiroshima), or (c) an independent yōkai figure appearing in liminal places. An Edo-period picture by Toriyama Sekien is sometimes associated with the name but the identification is explicitly uncertain; Sekien may also have been playing on the word 'ao' (青) meaning both 'blue' and 'immature,' suggesting a punning image of an inexperienced priest rather than a straightforward source-origin for the legend.

Typically described as a humanoid resembling a bōzu (priest/monk) with blue coloration—either a blue body, blue clothing, or a blue head/face. Regional variants emphasize particular visual contexts: a blue-bodied figure in vacant houses (Okayama), a priest's face with a blue head emerging from toilets (Yamagata, Fukushima), and an illustration possibly showing a one-eyed priest beside a thatched hut in Sekien's Gazu Hyakki Yagyō (identification with aobōzu is uncertain).

Behaviors and harmful acts attributed to aobōzu vary by prefecture. Recorded behaviors include kidnapping children from wheat fields at sunset (Shizuoka); delivering prohibitory warnings after a summoning-like action (Nagano); proposing dangerous suggestions (in Kagawa, asking women to hang themselves and attacking if ignored); challenging humans to physically dangerous contests (in Yamaguchi, small mountain-god aobōzu who can easily toss people); and startling/haunting users of school toilets by presenting a priestly face (Yamagata, Fukushima). In some localities the aobōzu is a shape-shifting animal (weasel, tanuki) rather than an intrinsically supernatural priest.