Shinkansen is the famous bullet train in Japan. It takes about 1.5hrs from Osaka to Tokyo. The ticket is crazily expensive. One-way trip costs more than $100 bucks. Unless you're in a hurry don't take the train. Night bus is cheaper but still costs around $50 for one-way and they're not very comfortable. I just want to have a one-time experience but when I come back I will take the night bus.