Abura Akago

Abura Akago is a kaii said to arrive at night as a fireball, attach itself to a household's andon (oil lamp), and transform into the shape of an infant to lick the lamp's oil before departing. The entity is documented in Toriyama Sekien's *Konjaku Gazu Zoku Hyaku-ki* (1779) with an origin account: an oil merchant from Ōtsu in Ōmi Province (present-day Ōtsu, Shiga Prefecture) who stole oil during his lifetime became this being after death, compelled to steal and consume oil in spectral form.

In representative legends, the oil merchant—having been a thief in life—transforms into a fireball that flies through the night sky. Drawn to the glow of household lamps, the entity enters and assumes the shape of an infant, licks the oil, and departs. The phenomenon was understood within the context of oil-lamp culture in Ōmi and Kyoto regions; the gradual depletion of andon oil was attributed to Abura Akago's visitations.

The entity's earliest known textual appearance is in Toriyama Sekien's work (Anei 8, 1779). Variant accounts appear in early modern kaidan collections and popular narratives. From the modern period onward, folklorists including Yanagita Kunio integrated discussions of Abura Akago into broader studies of fireballs and the souls of the deceased. The entity was established as a distinct entry in *Nihon Yōkai Daijiten* (2005, edited by Murakami Kenji) and is recorded in the International Research Center for Japanese Culture's Database of Kaii and Yōkai Legends.

Related phenomena include "oil-stealing" beings and the "Oil Monk" (associated with Atago Mountain, Kyoto). Abura Akago is distinctive for its specifically infantile form. As a fireball-like kaii, it shares characteristics with human souls and foxfire in the broader taxonomy of nocturnal luminous phenomena.