The convenient way for getting from Osaka to Tokyo is by highway bus! Not only is it considerably cheaper than the bullet train or plane, but the amount of the destinations available make it a worthwhile alternative.
We have buses departing from Umeda (the center of Osaka), Namba (popular with foreign tourists), the gigantic Rinkuu town outlet store near the airport and the crowd-pleasing Universal Studios Japan.
You can stay out late having fun shopping or eating and then take a bus to Tokyo.
Highway bus takes about 8 hours (Actual times vary by bus) which can allow you to get some sleep and taking the night bus can also save you the cost of one night in a hotel.