NAGAREYAMA, Chiba Pref. -- As night falls, all the houses in this quiet bedroom community melt into darkness.
Except one.
Lit up like a sightseeing spot, the two-story house in the city's south end is under 24-hour watch -- by local police and Public Security Investigation Agency officials, who have set up a surveillance tent on the property's perimeter, as well as by local residents, who built a watchtower next door.