How to go to Osaka from Tokyo

I would like to ask for your help how can we go to Osaka from Tokyo with the following schedules:

Mar 24-26, 2015 - Tokyo
Mar 26, 2015 - travel to osaka - how?
Mar 26 to 29, 2015 - stay in osaka and kyoto
Mar 29, 2015 - back to tokyo - how?
Mar 29 to april 1 - tokyo

Can you help us to go to tokyo what is the best transportation to use? How many hours going to osaka from tokyo if we will ride in shinkansen or Japan pass? Thank you

Shinkansen (Nozomi) 153-156 minutes (2:33-2:36 hrs.)
Shinkansen (JR Pass) 180 minutes (3:00 hrs.)

Airplane HND to ITM 70 minutes (1:10 hrs.)

And remember that to catch a plane you have to catch a train to the airport and get there around an hour before your flight, and then catch a train from the airport to the city. When catching a train, you depart and arrive in the city, and don't have to be there too much earlier than your train leaves.
Flying can be cheaper with a budget airline (e.g. Peach), but if you buy a 7-day JR Pass it will pay off with the round-trip Tokyo-Osaka-Tokyo. If catching a train, try to do this in the evening so you don't waste daylight hours.