I realized at the airport that I left my luggage at the hotel. I'm unsatisfied that the hotel didn't contact me.

Japanese law requires that the person who finds lost property must promptly return it to the owner or report it to the police. Therefore, while some hotels will contact the owner if they know who it belongs to, others deliver it to the police without notifying the guest who has checked out. It is advisable to check carefully that you have not left any items behind when you depart.