I don't know how your trip schedule lines up with your wedding schedule (or whether the 2 are joined at the hip). But - for a first and perhaps only trip to Japan - I'd recommend Cherry Blossom season in the spring. It's gorgeous.

My husband and I will be taking our second trip to Japan this year. Our first was about 2.5 weeks (7 nights Tokyo/5 nights each Kyoto and Osaka). But we are a lot older than you are and find that it's easier for us to travel in larger cities as opposed to countryside these days. Robyn