The Suspended Ceiling Legend of Utsunomiya-jo Castle

In the early Edo era, the 3rd Shogun Iemitsu TOKUGAWA came to pray at Nikko Toshogu Shrine and decided to stay at Utsunomiya-jo Castle overnight on his way back.
Having come to know this travel plan, Masazumi HONDA, the lord of Utsunomiya-jo Castle attempted to assassinate Iemitsu by making a suspended ceiling built with a trapping device.