28 day tour plan

I have drawn up this itinerary for my one and only visit to Japan could you please comment...
Day 1 Narita - Tokyo Tsukiji - Akihabara - Ginza (night)
Day 2 Tokyo: Asasuka - Ueno - Imperial Place
Day 3 Tokyo Shibuya - Tokyo Tower - Roppongi Hills
Day 4 Tokyo Day trip - Kamakura
Day 5 Tokyo Day trip - Nikko
Day 6 Tokyo Day trip - Toshigi
Day 7 Tokyo Spare or Yokahama day trip
Day 8 Tokyo-Kyoto Gion District -Nishiki market
Day 9 Tokyo Kiyomizudera Temple and Sannenzaka / Higashiyama /Ninenzaka area
Day 10 Kyoto Kinkakuji Temple - Ninnaji temple ( Best gardens)
Day 11 Kyoto Arashiyama - Bamboo Groves (maybe Romantic train)
Day 12 Kyoto Nijo Castle - Imperial Palace
Day 13 Kyoto Fushimi Inari Temple (1000 Steps)
Day 14 Kyoto Heian Jingu Shrine
Day 15 Kyoto Day Tour...Okayama
Day 16 Kyoto-Hiroshima-Miyajima
Day 17 Miyajima Mount Misen and
Day 18 Miyajima - Osaka Kuromon Ichiba Market /Den Den town /Shinsekai /Tennoji Day
Day 19 Osaka Kita & Umeda / Osaka castle / Nakanoshima Park.
Day 20 Osaka - Kanazawa Kenrokuen Gardens
Day 21 Kanazawa Touring
Day 22 Kanazawa-Takayama Touring
Day 23 Takayama Shirakawa-go
Day 24 Takayama Gujo Hachiman
Day 25 Takayama- Nagoya Nagoya castle
Day 26 Nagoya Toyota Tour then to Tokyo
Day 27 Tokyo.. Spare day
Day 28 Narita Home

It looks quite good to me.

Day 5 Tokyo Day trip - Nikko
Day 6 Tokyo Day trip - Toshigi

Note that Nikko is also located in Tochigi. Depending on where in Tochigi you plan to go on Day 6, you might consider combining the two into a 2-day side trip.

Day 15 Kyoto Day Tour...Okayama
Day 16 Kyoto-Hiroshima-Miyajima

Okayama is on the way between Kyoto and Hiroshima. You could consider visiting it along the way rather than in a daytrip.

Day 22 Kanazawa-Takayama Touring
Day 23 Takayama Shirakawa-go

Shirakawago is located between Kanazawa and Takayama. I strongly recommend to visit it along the way between the two places. There is a direct bus between Kanazawa and Takayama that stops in Shirakawago along the way.

We went to a lot of these places last year.
My main advice is try to plan your days so that you don't visit the major tourist sites on a Saturday and particularly a Sunday. (ie. Nikko, Shirakawa, Kamakura)

We went to Shirakawako on a Sunday and it was ridiculously packed with Japanese tourists. I think we stopped counting at 83 big tour buses in the Shirakawa area PLUS all the private cars. It was crazy!

Good suggestion Uji I overlooked that,can you suggest the best way to get early transport 7 am to Shirakawa-go and on to Takayama I presume at least 6 hours would be required for Shirakawa-go

Stewy63 its funny you mentioned the crowds I was worried myself about this and any poor weather I might run into and as this trip is as much about recording it as seeing it I am thinking of including a few more free days as I have nothing but time, its just a question of where to include them