Currently, I am the only male in the house. There is a door in my room that goes to the bathroom. The door was missing a doorknob, and therefore had a large hole in it. This was a problem.
So my housemate Hana dug into a sack of doorknobs (until now, I thought those things were just figures of speech!) and we installed one in the door. It was very surreal. Now there is a door that can be used to enter my room, but not exit it.
Amusingly, if my housemates use the bathroom while I am listening to music, they can shower to a soundtrack.