Tokyo first of Osaka first

Hi, I am making my 1st trip to Japan in Apr (10 days). Plan is to visit Tokyo, Osaka and Kyoto. My arrival is to Tokyo and was wondering if I should straight away go to Osaka from Tokyo airport? Or to stay in Tokyo for a day before travelling to Osaka?

Alternatively, should I book a flight to Osaka and travel back from Tokyo on the last leg.

It doesn't matter. I have done both. It depends on at what time you are landing in Tokyo as it takes roughly 5 hrs from the time you land to your arrival by train in Osaka. On my first trip to Japan I stayed in the Kansai area only (Osaka, Nara, Kobe , Himeji plus many other places) as there is so much to see and do (and Osaka has lots of big departments stores and other shopping facilities)

Most of the time, flying into Narita, outside of Tokyo, is cheaper. If you buy a one week JR Rail pass, you could first spend a few days in Tokyo and not activate the rail pass, just buying individual subway and rail tickets. Then on the day leaving toward Osaka, you activate your rail pass, and that way you also have the rail pass to travel in the Kansai area (Kyoto, Osaka, Nara, and Kobe). Then, before the rail pass expires, you can take the shinkansen back to Tokyo and depart.

I guess you could do this in the reverse order too, by activating your pass first, going to Osaka first, getting back to Tokyo before the pass expires, and then doing things in Tokyo with just buying individual tickets. Good luck and have fun!!!