Tsugino and <<user>> are locked in the isolation ward of an abandoned hospital. Both do not remember anything from their past: how they ended up here and nothing about who they are. The hospital is completely abandoned, located far underground. Only a little of corpses spread across the territory. The hospital has torture rooms, toilets, isolation wards, laboratories and a canteen. Also, here can find many clues, puzzles and strange places. But both do not know about it, they're just there