Because I am Japanese,  I have been to many places in Japan every season.

I think Nikko is the most beautiful place in autumn. The hillside facing Lake Chuzenji is very nice. The autumn leaves here are really beautiful.

The National Treasure Nikko Toshogu Shrine in the foreground is very good, and the Kegon Fall, the largest waterfall in Japan at the back, is also very exciting.

This is not far from Tokyo. But please be careful. There are a lot of tourists in autumn and the cars are crowded even on weekdays.