If you're at all into the world of Sanrio, this is the place to be. Hello Kitty is certainly their biggest seller, and she is out in force along with all her friends -- during certain times of the year they have events where there is actually an employee in a Hello Kitty suit hugging kids outside the door. They also specialize in some of the harder to find Hello Kitty items (in the back behind the counter) like the toaster (I'm not sure if they actually carry the infamous Hello Kitty vibrator, though).
What I love about Sanrio is that even for someone who is only mildly interested in Hello Kitty, like myself, there are so many options -- stickers, pencils, shirts, gifts, etc. I have ducked into Sanrio killing time before a movie on 42nd street and ended up happily purchasing a mini notebook or tiny tupperware set. Crazy, I know, but such is the magic of Sanrio.
Lots of silly, kawaii fun.