[Episode 18: Bound Ground] Mount Sashiro. [Trailer]

This is the trailer for Episode 18, “Bound Ground.” It covers Mount Sashiro in Kasama, Ibaraki Prefecture, and Kasama Castle ruins on its summit.

Kasama Castle is said to have been built in the Kamakura period by the Kasama clan, and in the Edo period the Kasama domain’s government office was located there. Most buildings were demolished under the Meiji-era castle abolition order, and now only parts of stone walls and moats remain in the mountains. The foot of the mountain is maintained as Sashiroyama Foot Park, known for cherry blossoms.

The trailer introduces the investigation at this castle site. The main episode is a single video shot in daytime. Some books and websites list the location as Kashima City, but the correct location is Kasama City.

What to Watch For

Before the trailer, follow the mountain castle’s history a little. In the Kamakura period, two Shingon temples were fighting for power around Kasama, and the weaker side asked the Utsunomiya clan of Shimotsuke for help, so Kasama Tokitomo, a relative, was sent. Work on the summit castle began in 1219 and was completed in 1235, it is said. The Kasama clan ruled for eighteen generations, but after the 1590 Odawara campaign, the eighteenth head, Tsunaie, was attacked and destroyed by the head family, the Utsunomiya.

Our Take

Tokitomo, who entered by exploiting the conflict between the temples, is said to have been turned on even by the warrior monks who had been his allies, and ended up destroying both temples. The Kasama clan in turn ended by being attacked within the same extended family. This is speculation, but a run of events in which allies became enemies and kin turned blades on kin must have left deep suspicion and exhaustion in the people who lived through it. We think the ground for the fall of a castle and extinction of a clan to be told as stories of “resentful spirits” lies in the mountain’s own history. We have, however, confirmed no historical source tying it to any specific ghost.