Instructions on how to get there are posted on the walls of the subway with big yellow arrows.
It's actually simple, from Namba station (where we stayed) ride the train bound for Nishikujo station (Hanshin railway) and from there transfer to the JR Sakurajima Line with the last stop at Universal City. From the station it is a 5min walk through Universal City Walk.
If there's one thing that this place have and the other US don't, it's the WIZARDING WORLD OF HARRY POTTER!
(Please see here for the rates and tips on getting a USJ ticket)
The place is a replica of the Hogsmeade, where shops covered in snow are while selling Butterbear, Olivander's wand, items from Zonko's and a lot more. The castle reflecting in the black lake and Hagrid's house should not be missed as well.
One of the rides that one shouldn't miss is the Unexpected Journey inside the castle! It's an awesome indoor ride and a thrilling one as well. Aside from that, the Flight of the Hippogrif is the only other ride you'll find inside. But if you're a real Potterhead this would do.
PS. Do visit Olivander's Wand Shop ;)
Aside from the Wizarding World, there are a couple of attractions you can visit. Sadly most of the rides were under maintenance when we went there. Jurrasic Park, Hollywood roller coaster and the others. To be sure of the schedules look here.