Got money to spurge on theme park? :P here's some of em

As you guys know, there's a spa world near Hotel Toyo in Osaka, good for the cold i guess, so go check it out

In Nikko (2 1/2 hrs train away from Tokyo o_0)
Edo wonderland Nikko, A recreation of Tokyo in the Edo era (1800s). The emphasis is on fun, rather than education; don't miss the action-packed ninja show or the "Hell Temple" haunted house. In fact, a glowing Buddha statue signals your departure from hell at the end of the obstacle course

In Ise, also a similar attraction to Edo Wonderland Nikko, but closer to Osaka
Edo Wonderland Nikko, which is different than the one in Nikko because it has a NINJA MAZE (with traps and hidden walls, like those in video games ><)

Oh there's this interesting theme park where Tokyo dome is (big indoor stadium where a lot of celebs hold their concert )
[url]Tokyo dome city[/url] and they have this rollar coaster that goes thru a hole in a BUILDING OUTDOORS ><
I went there too late the last time I was there, and had to go home without tryin the rides

Now another one near Osaka, Universal studios Japan

And the most famous of all LUV IT OR H8 IT*click* *WARNING for the young hearted XD*