Amanda Beale's on her way to school, just like every other kid that morning. The difference? She's got a suitcase.
The suitcase makes Maniac think he's found another runaway, so Amanda gets a "hi."
But wait, Maniac's in the East End, "where almost all the kids were black" (3.3).
Luckily, Amanda is as friendly as Maniac, so he gets a "hi" back.
Maniac then finds out that Amanda isn't actually running away.
So what's up with the suitcase? Turns out Amanda loves loves loves books.
Lugging them to school each day in a suitcase is the best way to protect them from her little sister and brother, who are overly fond of crayons; and her dog, who will chew anything he can.
Maniac likes books too, so they start talking. Maniac is able to convince Amanda to lend him a book.