Japan is a country that appreciates the seasonal changes much more than other countries that I know of. Vegetables and fruits are made available depending on the season, and menus at restaurants change accordingly as well. Crave mangos in winter? Tough luck. But I'll have to admit, experiencing the changing seasons in Japan not like it is anywhere else I've been. The cherry blossoms in Spring, lights in the winter, and kouyou-changing colors in fall.
They have Japanese gardens and parks designed to be beautiful throughout the seasons, full of various colors that appear throughout the seasons. A great place to go to is the Shinjuku gyoen, althogh there is a small fee to pay. It is a large park full of various trees, with orange, red, and yellow.
Another great place to view the changing colors of the leaves is in Daikanyama. Not only can you see this traditional Japanese house, but you can enjoy the scenery(from inside and out). This place also has a small fee to enter, but it is definitely woth it.
[Kyū-Asakurake House ] 旧朝倉家住宅