What time of year?
With 35 days there's no need to stick to what would be done in 14-21 days at a normal pace.
As much as I like Osaka, 9 days is way too much. I'd reduce it to 2-3 days.
Also, you could reduce a couple of days from Tokyo.
You're already doing what would be day trips from Osaka such as Himeji and Kobe, there is no reason to stay in Himeji, there's not so much there beyond the amazing castle and grounds.
You have so many options, depending on your preferences, a few ideas:
1) After Nagoya, explore more of Chubu (e.g. Gujo-Hachiman, Takayama, Okuhida, Kamikochi,Nagano, Matsumoto)
2) From Okayama, visit Kurashiki visit the inland sea islands such as Naoshima, Teshima and Shodoshima, or go to Onomichi (on the way to Hiroshima) and cycle the shimanamikaido for a few days to explore the inland sea islands there
3) Spend a week in Hokkaido or Tohoku or Kyushu, depending which appeals more (and time of year), they're all wonderful.
I'd try and visit at least one of the nice onsen towns, it's IMO an essential part of a Japan trip.
https://www.japan-guide.com/e/e623a.html