There's a boy in the Girl's bathroom by Louis Sachar

Bradley Chalkers is a trouble maker. He never pays attention at school. He's mean to everyone, never does his homework, doesn't have any friends, and just doesn't care. Jeff Fishkin is a new kid. He has to sit next to Bradley. He is looking for a friend. Then one day Bradley finds a surprise, Carla Davis the counselor. "Just call me Carla, let's be friends," she said. When Bradley feels naughty, she just lets him talk and talk. Carla helps Bradley see things a different way and he begins to change, but then Carla leaves. Will things ever be the same again?

by Emma