Itineary Check - June-July 2023 with kids

Hello all! Our family (2 adults, 2 kids - 8yo, and 6yo) is headed to Japan for the first time in June-July for about 18 full days. I'm trying to settle our general itinerary before I decide on local attractions/sights. Any comments or recommendations are greatly appreciated!

Day 1 - June 21 - Tokyo - Arrive
Day 2 - June 22 - Tokyo
Day 3 - June 23 - Tokyo
Day 4 - June 24 - Tokyo
Day 5 - June 25 - Tokyo to Hakone
Day 6 - June 26 - Hakone to Kyoto
Day 7 - June 27 - Kyoto
Day 8 - June 28 - Kyoto
Day 9 - June 29 - Kyoto
Day 10 - June 30 - Kyoto to Osaka
Day 11 - July 1 - Osaka
Day 12 - July 2 - Osaka
Day 13 - July 3 - Osaka to Hokkaido
Day 14 - July 4 - Hokkaido
Day 15 - July 5 - Hokkaido
Day 16 - July 6 - Hokkaido
Day 17 - July 7 - Hokkaido to Tokyo
Day 18 - July 8 - Tokyo
Day 19 - July 9 - Tokyo - Depart

Some notes/questions:

-We usually like outdoors activities on our vacations, with some (easy) hiking. But when we go, it'll be in the middle of rainy season. Should I add another night to Hakone (or drop it altogether)? I've read that visibility of Mt. Fuji is not the greatest from there particularly during the rainy season.

-Is it worth trekking to Hokkaido for 4 nights? I'd probably fly from Osaka to Hokkaido to save some travel time. I was thinking that we would get a break from the heat in the Hokkaido area in July. Or are there good alternatives in the Japanese alps (or similar) where we may not hit as much heat and rain during this season?

-We were thinking about possibly renting a car for Day 5 to Day 13. How are the driving and parking situations overall if we were to make day trips, like to Nara and Himeji Castle? Or is taking the train/local transportation usually more convenient?

Many thanks in advance!

Hi!
I am actually looking to return to Japan around the same dates as you. :D

The rain is not so much of a problem usually, it's just the heat and humidity.

I would not want to try to drive from Hakone to Kyoto. I'm pretty sure none of the expressway passes are going to cover that route and expressway fees can be quite high. You can take all smaller roads but it will really increase your driving time.

Japan also has quite high drop off fees if you do not return the car in the same prefecture you rented it. Most places in Kyoto do not have parking and if they do, they are charging you for it. I would not want to drive in Osaka. There was a lot of construction when we were there in December. I can't imagine driving to Nara or Himeji especially since both are readily connected by trains. My general rule of thumb about driving in Japan, is if the hotels offer free parking and most activities have free parking, it might be worthwhile to drive it. If hotels all charge a lot for parking it might not be a time to drive unless you actually live in Japan. I can't imagine driving in Nara City. If you wanted to drive in the Sakurai area, I could see it, but Nara city is just not going to be fun. Himeji has some nice big wide streets between the station and the Castle, but you may as well just take a taxi.

I've never seen Mt. Fuji from Hakone and I have been a lot. However, I am looking at going back to Hakone again, because June is hydrangea season and the Tozan line is simply lovely when they are in bloom. I am also hoping to take my kid back to Yunessun since she is not as fond of real onsen anymore. A lot of people like Hakone because it is a very accessible area for foreigners who want to try onsen and ryokan.

I have been to the Japanese Alps in June/July. Places like Kamikochi were very cool, but larger cities like Takayama, Matsumoto, and Nagano, were still hot during the day though most cooled off considerably at night.

Hokkaido should be considerably cooler and a lot of people like to go there in the Summer, and yes, I would definitely fly!

An other vote against the car. Drop off fees, parking fees, low speed limits and complicated driving in major cities while all these cities have great public transport.

An other vote for Hokkaido. For me the only place where June / July is bearable. But I am not heat resistant at all. If you/your kids are anything like me, reschedule to autum/spring/winter or spend 2 weeks in Hokkaido.

I would advise against changing hotels from Kyoto to Osaka. Just stay in Kyoto and do day trips from there.

This is a Japanese point of view.

Tokyo is a big city. But Osaka, Nagoya, Yokohama etc. are big enough to recognize they are big. So honestly I don't want to stay long in Tokyo. Tokyo's public transportation is convenient, but in the morning and evening it is very crowded. I don't know where you are from, but as a former Osakan (Osaka is the second largest city in Japan), I think Tokyo's "rush hour" is crazy. You may want to see how crazy it is, but I strongly recommend you not to ride the train on "rush hour" time, especially with your kids.

The bright side of Tokyo is that it's a megalopolis. You can feel the hugeness from observatories such as Tokyo Skytree, Tokyo tower and Tokyo Metropolitan Government Building. Another place I recommend you is "Yurikamome Line".

https://www.yurikamome.co.jp/en/
https://www.youtube.com/watch?v=IlLdIDPNHn0&t=473s

You (or, specifically your kids) can take the front seat and see the landscape of Tokyo. I believe the front seat is for kids, and if you go on weekdays, there should be no Japanese kids. Yurikamome rarely gets busy. You may want to buy 1-day tickets (820 yen for adult, 410 yen for child).

Kyoto is the only one place where you can see so many temples/shrines in Japan. You don't need to go to specific temples/shrines: just walk around and you will find a famous ones in 10 minutes. There are many UNESCO's world heritage sites in Kyoto while in Tokyo there is only one (National Museum of Western Art, established in 1959, designed by Le Corbusier). Late June is not the worst season, better than July and August (less hot).

Hokkaido has 6 national parks. Among them I like Rishiri-Rebun the best, but others are also nice to visit. Two years ago I went to Rishiri and Rebun for 7 nights in the Covid-19 situation and was surprized that there are so many western tourisits (must be living in Japan).