I like this, send a letter to them and receive a small deduction of friendship or maybe only be able to do it once a weekIt'd be handy if you could leave a requested item in a mailbox or outside their door. Or maybe an amazon-style dropoff locker at the bulletin board. Maybe make it worth a few extra friendship points if you hand it to them in person? So it's worth tracking them down if you want to, but you don't lose out if you can't track them down because you don't know what their schedule is or you're not good enough friends yet to enter their room.