Why the Bell Tolls at Dusk

Mitozu - a small town lost in the mountains, population 6000. Every evening at 6 heavy bell tolls start resounding down the streets. Everybody knows that after the bell sounded you must not go out until the Sun rises again. But one day this law is broken by an ignorant outsider who just returned home after 10 years in Tokyo and the horrible apparition known only as Myoudo-sama has finally found a victim to prey upon.