Hokkaido or Fukuoka/Nagasaki?

Hello everyone,

I travelled to Japan for the first time with a friend 2 months ago. We've been to Tokyo, Kyoto, Osaka, Nara, Himeji, Kobe, Hiroshima and Fujiyoshida during our 3 week stay. I'll post a itinerary from my frist trip at the end of this post, if you're interested in seeing it.

Now I'm already roughly planning my next trip back for April/May 2025. My girlfriend, who has never been to Japan before, will accompany me this time. We plan on going for 21 days. As I'm trying to find a mix between the "can-skips" and "must-sees", I've got a few questions for the more experienced travellers here:

• Is Sakura season really as bad as everyone makes it out to be, when it comes to crowds? In May we obviously missed it with our route, but I'm contemplating going during April 2025 for the cherry blossoms. Although we felt Kyoto was super overcrowded at the hotspots, even when we were there. But it got way better, when we deviated just a tiny bit from the "main routes".
• Having seen the places I visited, would you recommend on shortening Tokyo, maybe even skipping Hiroshima and either fly to Hokkaido (possibility to see cherry blossoms) or Fukuoka/Nagasaki? If so, for how many days? Keep in mind, although I've been to Hiroshima and said I didn't necessarily need to go back, my girlfriend would be interested to see it. Also I haven't been to Miyajima, but I've been reading a lot of positive feedback about it on here.
• Do you have any other recommendations, I definitively should add to my itinerary? Nikko or Hakkone for example? We've been to Fujiyoshida for 2 days and even though Fuji was supposed to have a 10 visibility in the morning and afternoon, we didn't see it at all. So I'm kinda hesistant when it comes to Fuji, as it was our main reason for going and we completely missed it.
• Is it worth to spend a whole day to visit Super Nintendo World or other theme parks?
• My girlfriend and I are both vegetarians although I don't mind eating meat during holidays/special occasions, she will not. What has your experience been with vegetarian options? I didn't really pay close attention to it, but if I remember it correctly, a lot of the dishes come with added meat etc. Is it easy to order food, that usually comes with meat (most ramen for example) as meatless?

So far, I roughly planned to spend 4-5 days in Tokyo at the start, 2 days in Osaka, 4 days in Kyoto, 1 day in Nara, 1 day in Himeji (and Kobe?) and 2 days in Tokyo at the end again. This leaves me with 6-7 unplanned days at my disposal.

My itinerary from 2 months ago:

Tokyo
Day 1
(afternoon arrival)
Shinjuku

Day 2
Shinjuku+Shibuya

Day 3
Chiyoda + Chuo/Ginza

Day 4
Taito/Ueno/Akihabara

Day 5
Asakusa/Sumo ournament Kokugikan 

Kyoto
Day 6
Nijō castle 
Nishiki Market 

Day 7
East of Kyoto, starting from Jisho-ji and walk via Philosopher's Path southwards to Nanzen-ji

Day 8
Gion
Nishiki Market

Day 9
Arashiyama

Osaka
Day 10
Dotonbori

Day 11
Himeji castle + castle festival

Day 12
Nara, deer park, wakakusayama hill, surrounding temples

Day 13
Dotonbori/Nipponbashi Denden Town
Osaka castle

Hiroshima
Day 14
Hiroshima peace memorial
Hiroshima castle
Shukkeien garden

Day 15
Chill day in Hiroshima, afternoon shinkansen transfer to Tokyo

Tokyo
Day 16
Minato, Tokyo Tower, TeamLab Planets

Day 17
Fujiyoshida, Fuji-Q Highland

Day 18
Fujiyoshida, transfer Tokyo in the afternoon

Day 19
Mostly souvenir-shopping in Akihabara+Nakano broadway

Day 20
Transfer to Narita around noon