Cape's escape game

The main character recently moved to the apartment.
Because the rent was quite cheap, he was pleased with himself.
He did not seem to have any doubts concerning the cheap rent.
One day, just a few days after moving in, when he twisted the doorknob, thinking of going out, it would not open.
Cape, a mischievous ghost, suddenly appeared in front of the main character who was left wondering.
Of course, there was the reason why the rent was cheap.
Yes, a ghost was haunting this place.
The main character was locked in the room by Cape.
Let's solve the mystery and help the main character escape from this room.