u/AeolusTheGarlicKing

I am studying abroad in Japan this fall in Nagoya, I booked my flight when it was cheap about a week ago after I was accepted by my IES program. I got accepted by the university itself more recently and the packet says I cannot arrive before September 1. The issue is my flight arrives August 31 at 3:55pm in Haneda and 8:40pm in Nagoya. Will I be allowed to sit in the airport until midnight? Is this a limit due to my student Visa? I am a US citizen and planned to visit my family in Nagoya before the program move in on the 4th. I cannot reschedule my flight without just getting a full refund (the price is now much higher). What is the best course of action? Thanks in advance.