The Suspended Ceiling Legend of Utsunomiya-jo Castle

Because of this information, Iemitsu returned to Edo without staying at Utsunomiya-jo Castle and nearly had a narrow escape. The assassination plot ended in failure, and Masazumi HONDA got arrested and came to receive judgment of the Shogunate.
(This story is a legend created later, based on the incident in which Utsunomiya-jo Castle was confiscated suddenly under the Masazumi regime.)