First time travel to Japan

Hi,

I'm going to Japan at the end of february and going to stay for 4 weeks. I have flights booked and now am planning hotel stays.
I'm mostly staying in Tokyo, but plan on spending a week in Osaka and perhaps few days in Sapporo.
So my question is, at the time of my travel, is there enough to do in Sapporo to stay more than, say 3 days? What about week in Osaka?
From Osaka, I plan on doing some day trips to Nara, Himeji and maybe also Hiroshima. Kyoto can wait till my next trip.
My interests include culture, sports and bit of entertainment. Budget is, lets say above average.
Any recommendation is welcome.

Kyoto-Osaka is only 29mins away. Any particular reason for not including it? If interested in culture then Kyoto would have been on the list IMO.

Regarding Sapporo, Osaka- pl have a look below

https://www.japan-guide.com/e/e2163.html
https://www.japan-guide.com/e/e2157.html
Ditto Kyoto

if you�fre interested in skiing, you might need more than 3 days in hokkaido. onsen during winter is a nice experience as well.

For Sapporo check when the snow festival is. It�fs great, but difficult to get hotels. But definitely nice.

You know it's the snow season right? Most people go for the snow in Feb.

Snow sports yes. Other sports nope.
No hiking for you suggested locations.

We Love Hiroshima.when people visit hiroshi ma they fall in love with this city ,with people ,with its culture.You can buy
astram line 1 day pass=950 yen
Bihoku kotsu 2 day pass=2000 yen