Based on the erotic game by Lilim Darkness.

"I'll save you right away!" I try to open the door, but I can't.... I try again, but nothing happens.... "Do I need a key to open this door?" But I don't have enough time to look for it. I can't open it.... I can't open.... I can't.... "Noooooooooooooo!!" I hear your scream from inside.... I can do nothing.... You'll never come back... never....

(Source: Visual Novel Database)