Chikatetsu Fuusa Jiken "Naze Boku-tachi wa Koko ni Iru"

Main character is a normal university student. He goes to a part-time job before Christmas and gets in a subway crash. He wakes up in a closed space with another man and four women as survivors. They strive to escape this place, but somehow things get violent with many women insulted. Will protagonist help the girls or attack them?