Last minute Itinary help

I am a couple of days away from my first japan trip with my gf, and stressing!
The following is a basic itenary i have worked out so far. I have a few gaps i would like some help filling them in, aswell as general advice on my plans so far.
Im also unsure of where i should base some of my day trips from, kyoto or osaka..
I have only booked the first 5 days of accomodation so far, and have a jr pass also.
Your help would be greatly appreciated!

Day 1: Arrive in Japan Tokyo
Day 2: Tokyo - Shinjuku
Day 3: Tokyo - Ueno, Akihabara
Day 4: Tokyo ・Harajuku, Shinjuku
Day 5: Tokyo ・Mt Fuji - Day Trip
Day 6: Tokyo ・Odaiba, Akasuka
Day 7: Kyoto
Day 8: Kobe - Day Trip
Day 9: Kanazawa ・Day Trip
Day 10: Hiroshima - Day Trip
Day 11: Miyajima - Day Trip
Day 12: Nara - Day Trip
Day 13: Mie - Suzuka ・Day Trip
Day 14: Osaka
Day 15:
Day 16: Tokyo ・Tsukuba race ・Day Trip
Day 17: Yokohama ・Day Trip
Day 18: Nikko ・Day Trip
Day 19:
Day 20:
Day 21: Tokyo
Day 22: Leaving Japan Narita

Thanks, Alex

I recommend against visiting Hiroshima and Miyajima in two separate daytrips, but rather overnight in the Hiroshima area once. It saves you four hours on the train.

I'm assuming that you have a 14 day JR pass.
For day 7 I would be staying near Shin Osaka station and using it as a base for Kyoto and Osaka areas. It only takes 15' to Kyoto by shinkansen. Re-arrange things and spend nights 13 and 14 in Hiroshima then on day 15 travel back to Tokyo and pick up on your schedule.
You should include Himeji castle in to your Kyoto/Osaka time as well.

I wouldn't be so set on when you go to Mt. Fuji (I assume you're going to Fuji Five Lakes?). Be flexible. I would plan to go fairly early in the morning on a day when it's clear. If it's not clear, don't go. Look for forecasts. Going on a cloudy day wouldn't be worth it, because you won't be able to see the mountain.

If you bought the 14 day JR rail pass, don't activate it until you're ready to leave Tokyo. Just buy tickets one at a time in the Tokyo area. If you have the 21 day pass, then you're good.

I agree, you should stay in Hiroshima at least two nights, if not three. Also Himeji would be a good thing to see on the way to Hiroshima.

Also, as for the extra days or so, I would spend more time in Kyoto. As for a base for where to stay, Osaka would be the easiest place to find a hotel. Try near the Shin-Osaka station (the bullet train goes through there). From that station you can easily get to Kyoto, Kobe, Osaka, and Nara (which is a little bit farther). As I see it, you only need to find 3 hotels, one in Tokyo, one in Shin-Osaka (northern part of Osaka), and Hiroshima.

One other thing I'd do, is that if you want to be back in Tokyo by Day 16 for the races, I would spend a couple days less in Tokyo in the beginning (you could cut short the reservations you have in Tokyo for the first few nights), and then leave for Osaka/Kyoto a couple days earlier, and then spend the remaining last days you have blank in Tokyo.

Suggested altered Itinerary:
Day 1: arrive
2: Tokyo (one of these three days could be Mt. Fuji if clear)
3: Tokyo
4: Tokyo
5: Kyoto (day 5-11 can be in any order, just be based in Shin-Osaka)
6: Kyoto
7: Kanazawa
8: Osaka
9: Nara
10: Kobe
11: Mie-Suzuka
12: Himeji then Hiroshima
13: Hiroshima
14: Miyajima
15: Travel to Tokyo
16: Tokyo, Tsukaba race
17: Yokohama (day 17-20 could be in any order, unless you only have a 14 day pass, which you'd want to activate on day 5 in the morning before you leave to Kyoto and that way it will be valid through day 18 with going to Nikko)
18: Nikko
19: Tokyo (one of these three days could be Mt. Fuji if clear)
20: Tokyo
21: Tokyo
22: leave

Hope this helps. And don't think you should be stressed out. Accommodations shouldn't be hard to find. You'll have an awesome time.

Thanks for your help everyone!
I have made some amendments as per your advice.
Also we have a 21day jr pass to get around with.
Im propbably going to pre book the weeks stay in osaka before leaving just to be safe.
We seem to have alot planned, hopefully my gf and i can fit all of this in comfortably!

Day 1: Arrive in Japan Tokyo
Day 2: Tokyo - Shinjuku
Day 3: Tokyo ・Ueno, Akihabara
Day 4: Tokyo ・Harajuku, Shibuya
Day 5: Tokyo ・Odaiba, Akasuka
Day 6: Tokyo travel to Osaka
Day 7: Osaka
Day 8: Osaka - Kyoto - Day Trip
Day 9: Osaka - Kanazawa ・Day Trip
Day 10: Osaka - Nara - Day Trip
Day 11: Osaka - Kobe - Day Trip
Day 12: Osaka - Mie - Suzuka - Day Trip
Day 13: Hiroshima
Day 14: Hiroshima - Miyajima - Day Trip
Day 15: Hiroshima - Himeji travel to Tokyo
Day 16: Tokyo - Tsukuba race - Day Trip
Day 17: Yokohama ・Day Trip
Day 18: Nikko - Day Trip
Day 19: Tokyo - Tsukiji Fish Market
Day 20: Tokyo - Mt Fuji - Day Trip
Day 21: Tokyo
Day 22: Leaving Japan