You can do much in 4 days! I'd have to very highly recommend a day trip to Kamakura which is about an hour by train from memory. If you can't get to Kyoto this is a pretty good stand-in with lots of temples hills and trees and bamboo etc. A grand day out.
If you are prepared to get up early, like 4am, Tsukiji Fish Markets are an exceptional start to any day. almost 8 years ago