First time trip to Japan. Trying to catch the cherry blossoms. Will be going last week of March 2018 and first few days of April (roughly). 10-12 days.

Which itinerary is preferred? Starting in Tokyo and then heading south? Or starting south and moving up to Tokyo?

We'll be a family of 4, including 2 elementary school aged kids. Another family of about the same age will be joining us, if it matters.

Due to points (likely flying ANA), if we want to start in Osaka, we would either have to fly to Tokyo and then a domestic to Osaka or take a bullet train from Tokyo. Can't fly directly to Osaka. No issues starting in Tokyo and leaving out of Osaka.

I suppose I could do a roundtrip Tokyo - Osaka - Tokyo, but that seems like extra unnecessary travel.

Any suggestions, comments, etc. Such as how long to stay in each city? Potential luggage issues since the kids might not be able to pull their own weight? I'm not opposed to side trips, but I'd rather limit them in order to more fully experience Tokyo, Kyoto, and Osaka (in that order). TIA