Well, we've worked on this a bit from the last post and have decided to par down a bit, but we are also willing to do a bit of traveling to see as much as possible. Here's the new itinerary:
Arrive in Tokyo in the evening of Day 1
Day 2-3 Tokyo
Day 11-13 Mt. Koya
Day 13-15 Tokyo
We would welcome any additional thoughts, and we were wondering if it made sense to go from Mt. Koya to Osaka and fly back to Tokyo as it seems like a very long bus/train trip.