Jippōzan Daijoin Temple (Oni Mummy)

Juhozan Daijoin is a small temple of unknown founding date in Yokkaichi, Usa City, Oita Prefecture. According to local tradition, the 'Oni (Demon) Mummy' housed here was once privately owned, then purchased in 1925 (Taisho 14) by a temple parishioner for 5,500 yen based on a bill of sale from Shimonoseki identifying the object as 'Oni-kei Kotsu' (demon-form bones) (Japan Mystery Database). Shortly after the purchase, the parishioner fell ill with an unexplained illness; after donating the mummy to the temple around 1929–30, the illness reportedly resolved. In the early Showa period, a forensic examination by Kyushu University suggested the mummy may be composed of human female bones and animal bones, but no definitive identification has been made. The mummy is enshrined not as a temple treasure for display, but as a 'personal devotional object' (jibutsu) that continues to receive religious veneration.

The bill-of-sale label 'Oni-kei Kotsu' ('demon-form bones') indicates this mummy participated in a historical market for unusual curios—oni, kappa, and mermaid mummies—that circulated among temples and shrines from the late Edo through Meiji periods. Most such objects are understood as fabrications combining bones and skins of multiple animals using taxidermy techniques (japanmystery.com). However, what sets Daijoin apart is that the mummy is not exhibited as a curiosity but actively venerated by the local community as 'Oni-san' ('Mr. Demon'). This reflects a broader Japanese folk tradition of enshrining beings from outside the human world—oni, tengu, snakes—as protective local deities.

Usa City's tourism office lists the mummy as an official tourist attraction (Usa City), and Oita Prefecture's tourism site also features it (visit-oita.jp). The local community calls the mummy 'Oni-san,' treating it not as a spectacle but as an embedded part of local religious culture. The temple is normally unmanned; during visiting hours the main hall door is open for self-guided worship.

Open year-round, 9:00–16:00. Crowds are generally sparse. A weekday morning visit in spring or autumn is recommended for comfortable stair climbing.

Photography within the precinct is permitted, but photographing the mummy itself is prohibited (MapFan). The 108 stone steps and the main hall exterior may be photographed. A low-angle shot looking up the stairway conveys the atmosphere well.

Photography of the mummy itself is prohibited. The 108 stone steps are steep; those with mobility concerns should exercise caution. The temple is normally unmanned. Parking for 10–15 vehicles is available free of charge.