Don't sit for long periods of time. You on a laptop? I am sure people on EF can keep you awake. If you really can't take it anymore, spray cold water on your face and neck. Find someone to talk to. Do something that keeps you busy. I have heard a lot about girls getting raped in hotel rooms.. so i understand why you are not in one. I spent 12 hours at a airport once, but japanese are nice and smaller so you don't have to worry about falling asleep.