5 Days in Tokyo and Osaka All In

My plan is to explore Tokyo and Osaka (just Universal studio to be specific) in 5 days all together with my best friend. What is the best way to save on transportation? I have read IC cards and bullet trains and what not but its confusing now haha. Which one you think is best in my situation? And also suggestions where should I stay in Tokyo is hotel near Tokyo train station sounds like a good choice? Thanks for all your help :).

Personally, I would just pick one or the other area with only 5 days as you will waste too much time and money on travel. If Universal Studios is a must, then I would fly into Kansai Airport, stay in Osaka/Kyoto and skip Tokyo.

However, if you won't listen to me and want to make the round trip, this is probably your best deal on train fare between Tokyo and Osaka and back, and it's the fastest train. https://www.japanican.com/en/tour/detail/PAS1J02131MKC/

I'm with me2: either go tokyo or osaka, pick one don't do both. (to save time and money)

I would also recommend one of Tokyo or Osaka to really see the sights properly. But if you must see Tokyo AND Universal Studio, and you want inexpensive transportation, you might want to look into overnight bus.