八菅神社, Shinto shrine in Aikawa, Kanagawa, Japan

Hakusuge Shrine (八菅神社) stands on Mount Hasuge in Aikawa, Kanagawa Prefecture. It is a Shinto shrine that was a major Shugendo center in the Middle Ages, when it was the mountain temple Hasuge-san Kosho-ji, with halls on the summit and at the foot and a settlement of some 52 monk quarters. Three large stone stupa-like tablets (碑伝) from 1291, 1552 and 1841 are kept here, and the shrine grove is a prefectural natural monument.

The mountain was opened, according to the shrine's three origin legends (1786, 1809, 1840), by En no Gyoja in 703, and Gyoki built a seven-deity Gongen temple in 709. In the medieval period it was a major Shugendo centre under the Shogo-in of Kyoto; the Hachisuge mountain records of 1826 list 52 cloisters, reduced to 34 by the late Edo period. In 1868 the separation of Shinto and Buddhism dissolved the Shugendo community, and the site became the village shrine Hachisuge Jinja.

The name Hasuge derives from a legend: when En no Gyoja carved three images here, eight stalks of white sedge (hassuge) sprouted from a pond. Under the Shugendo mountain temple Kosho-ji, seven gongen deities were worshipped, with Kumano Gongen at the centre alongside Zao, Hakone, Otokoyama Hachiman, Sanno, Hakusan and Izu Hashiri-yu. The spring grand festival revives Shugendo rites with a shibito goma fire ritual and hiwatari, walking barefoot over embers.

Access is by bus from Hon-Atsugi Station on the Odakyu Odawara Line (routes 厚59, 厚60, 厚64, 厚66, 厚96) or from Ebina Station's west exit (route 海09), getting off at Ipponmatsu stop and walking 20 minutes. The Aikawa town loop bus Naka-Tsukui-Nanbu route stops at Ikoi-no-Mori entrance, 6 minutes on foot. The shrine grove is a Kanagawa Prefecture natural monument.

The shrine keeps three large stone steles called hitaki, left by mountain ascetics: one about 3.8 m tall, erected in 1291 by the practitioner Nagayoshi with two companions, one of about 2.3 m from 1552, and one over 6 m tall from 1841, when Prince Yujin of the Shogo-in in Kyoto visited the mountain.