Ai,ayoungprostitutespecializingincostumefantasy,decidestohavesomefunbydressingasapoliceofficerandquestioningpeoplearoundthesiteofarecentmurder.Sheisinvitedtolunchatonehouse,onlytodiscoverthatherhostisthemurderer,heisholdingafamilyofthreeashisprisoners,andnowAiishisfourth.Astimegoesby,thekiller'sinsanitybeginstoruboffonAiandthefamily,untiltheybegintoshareinhiswarpedviewoftheworld.