bought the plane tickets to japan: arriving oct 3rd, 8am.

been checking out how to buy bedding for 2 days now; cheapest seems to be buying it online at a store called "nitori", which does free delivery. the problem is 1, what kind of ID can i show the postman? does my passport work? and 2. will i be too busy/away from the student apartments to be able to pick up my package when the postman arrives? i really don't to go 1-2 weeks without a bed and blanket... in october....