Not a direct answer to your question here, but it's good to note that "sakura season" is rather fluid. It was quite early this year and people are talking about it as a symptom of climate change. That could be, but then again next year it might be a week later than normal. In other words, assuming the borders are open, you might need to be flexible once arriving in Japan to visit places where the blossoms are in peak form. There are several websites that predict and track the cherry blossom season. Predictions usually start after the New Year holiday. For example:
https://www.japan-guide.com/sakura/