Dokumushi: Toxic Insects(2016)

Original title: ドクムシ

7 strangers are locked up in building. There is nothing to eat in the building. They see a big stock pot, a butcher‘s knife and a watch to count 7 days. The 7 strangers are locked in the building for 7 days and they have to kill each other until there is only 1 person left. The 7 people go insane due to hunger and stress.