When you arrive in Japan, go to the English-language section of one of the major bookstores (Kinokuniya Shinjuku is good) and find the English-language travel guides to Japan.

I remember seeing books about hiking in Japan and day trips out of Tokyo and Kyoto, but not any specific titles. However, there are more English-language guides to various aspects of Japan available in Japanese bookstores than there are in any Western country source, including Amazon.