They have kind of a little "show" since the bus blares music and the characters make a big deal about getting off the bus, dancing around while they're being escorted to the places they'll stand for pictures and autographs, etc. The bus blares music the entire time. Then they'll make another deal about getting back onto the bus. It's cute, actually. The CMs with the characters make sure orderly lines get formed and nobody rushes them. The fewer people around, the more interaction you're likely to get - some of the less popular characters are sometimes hanging out by themselves and like having someone to play with. These are generally "big head" characters - I don't remember seeing any face characters on the bus.