Sanrio Puroland is a little over an hour's train ride from Tokyo Station, longer if you don't take the express train. One of the many things to know is that Tokyo is a town and it's own prefecture (state/province) so it covers a rather large area.
Sanrio Puroland is in Tama 'New' Town(New as in New York, New Jersey) and outside of Tokyo Proper the purple special wards in the map above. So it's pretty far from Tokyo. I would reccomend deffinately planning this for a full day, we got in about an hour or two after they opened and didn't do everything when they were kicking us out of the building when it closes at an early (common for most Japanese establishments) at 1700 or 5pm. We were able to go on most of the rides see one of the 3 shows going on thought the day and see the "Arigato Everyone" Parade celebrating Kitty-chan's 40th anniversary .
As we walked from the Odakyu Tama Station, we noticed clues we were in the right area. Sanrio Charaters on posters, statues. You turn a the corner and see...
A lot of photos make it look larger than it really is. I'd guess its about the size of a medium sized mall. There are tons of things to do: rides, special exhibits, games, etc. Beyond this facade is the entrance, a place to eat, coin lockers and the always present gift shop. Everything is inside so a great idea for a rainly day in the Kanto/Tokyo area. Check the website for coupons (yes, coupons) to shave off ¥200 yen for the passports which are all you can eat ticket for everything. They apparently sell cheaper tickets that don't cover all the rides, shows, etc. A Day passport at the time of this writing cost ¥3800 (about $38 USD).
On most of the attractions there was an opportunity to buy a commemorative photo ranging 300¥-1500¥ and in my opinion worth it. Characters wonder throughout the park and chances to take photos with them are abound.
A lot of Japanese attractions have these commemorative photo, tourist trap. I almost always pay for them because, when else are we going to be in Japan? I'd pay more good photos of Kelly and I to have around. So be prepared to carry a bit more money for these easy to transport memories of the places you visit.
What did I think of Sanrio Puroland? I could say it's an overpriced, aging attraction but that doesn't quite capture it. Throughout our various trips around Japan I've never felt an attraction was crouded or busy and during out week day stay I never felt uncomfortable. I don't know if I personally would have gone out of my way to go visit but Kelly really wanted togo.
I think Japan is generally two faced; there's the weird, cute, different public face and the restrained, formal, quaint face. Living in Japan it's easy to forget were you live, then you visit a place that reminds you of Japan's other face. I have the same opinion of Robot Resturant, you forget that you live in Japan.
You'll hear about a place and think, 'I'll never go there!' and then you do and it was awesome. That's how I feel about most of my trips, and just how hard it will be to go back to Chicago.