Busy, busy, or a perfect scheme

Hi there!

Only a few weeks left before my plane touches down in Japan (3rd of August till 25 th of August). And honestly, I can't wait before that's gonna happen. I've followed the advise in the forum by setting up a itinerary and i've already booked most of my hostels. But I was just hoping that you would like to confirm it and tell me if I'm planning it perfectly or totally wrong in your opinion!

My Itinerary is as followed:

Tokyo -5 Nights
Mount Fuji - 1 Night
Ise: 1/2 day trip
Nara: 2 nights
Mount koya: 1 night
Osaka: 1 night
HimeJi: 1/2 day trip
Hiroshima: 2 nights
Beppu: 2 Nights
Kyoto: 3 Nights
Takayama: 1 Night
Kanazawa: 1 Night
Nikko: 2 Nights
Tokyo: 1 Night

I've planned to start in Tokyo and stay here for 5 days to explore the biggest attractions in the city. The fish market, shinjuku, and the other highlights.
After Tokyo 1 night at Mount Fuji (5th base at the mountain) for taking nice pictures and everything
Then to Nara with a short stop in Ise. After nara 1 day Shinjokin-Ji temple and enjoy the good life in a beautiful temple. Then to Osaka to see the hightlights over there, And then to the famous Castle where I would love to spend a few hours. Afterwards to Hiroshima, where i will stay 2 nights, 1 day in the city, the other day to the small Island where i would love to see the Miyajima Shrine. after Hiroshima to Beppu for the 7 hells. then Kyoto for the temples. Takayama and Kanazawa and finishing in Nikko.

Is this too much for a 3 week stay or is this achievable in 21 days without rushing through the country and the sights. I really hope i planned it good because i would love to see a lot in Japan since it's really hard for me to go there again soon. But I want to enjoy it as well without rushing on the other hand.

It is busy, but doable. Only the section where you visit Mount Koya, Osaka and Himeji within only two overnight stays, seems rushed to me.

Also, I recommend to visit Kanazawa before Takayama:

Kyoto - (JR train) - Kanazawa - (non-JR bus) - Takayama - (JR train) - Tokyo

You can save quite a lot of time by traveling in that order.