Yonkai no Yokai

From BoardGameGeek:

The hotel you chose in Tokyo had pretty good reviews, but something seems off. The attendant at the front desk seemed nice enough, if maybe a little anxious. You've checked in and are heading up to your room. The elevator doors open on the second floor (nikai)...wait, did you see that? The doors close and open again on the third floor (sankai). I swear I saw something down the hallway - you really didn't see it? The doors close and open again on the fourth floor (yonkai) - hold on...did you just hear "Yokai?" What is happening here?? Yonkai no Yokai is is a climbing/shedding game for 3-4 players. Only sets of the same value may be played. To increase the number of a cards in a set, you must decrease the value of the cards. Once sets of 4 have been reached, you can start reducing the number of cards in sets by increasing the value of the cards. -description from the publisher