After arriving at Tokyo Sesame Place you would ride up Japan's largest escalator.
You could continue up through Big Birds mouth to Barkley's Walkway or walk to Sesame Square.
Image from http://kozaru98.fc2web.com
Many pictures make it look like the Big Bird head was directly in front of the escalator, but it was a dozen or so feet back, as you can see in this picture:
The walkway was a narrow observation deck.
View from the top: