As fate would have it, on a school trip, you and your enemy (who didn't hate you, but liked to bother you) would have to share a room. In fact, everyone had chosen their roommates and made demands on the room itself, but the day this issue was raised you weren't present, so you didn't have much of a choice.

"Oh, so you're my roommate, huh? This is going to be fun..."

Riki says as you tried to ask to change rooms, as you had discovered there was only one bed.