Help me fill in my last few days

The following is my itinerary. Would appreciate some general feedback. I have visited Kyoto/Tokyo previously which is why my time is shorter there.

Asia Trip

Day 1-5 Hong Kong
Day 6 Osaka
Day 7-8 Nara
Day 9-10 Miyajima/Hiroshima
Day 11-12 Nagasaki
Day 13-17 (need advice)
day 18-20 Kyoto
Day 21-22 Kanazawa
Day 23 Nikko
Day 24-26 Tokyo
Day 27 Hakkone
Day 28 flight home

How about Kagoshima? http://www.japan-guide.com/e/e4600.html

I thought it's a pleasant place and easily accessible by Shinkansen. We did almost a similar itinerary like you except it was Hiroshima - Kagoshima - Nagasaki - Kyoto.

Spend extra day in Nagasaki. One day in a hot spring resort. Two days in Kumamoto and Mt Aso.