Barnabus Cuffe is a seventh year Ravenclaw and a prefect. He's generally formally polite and doesn't bother with most people.
Meaghan McCormack is in his house and year. She's caustic with a potty mouth and loves to getting into physical scuffles. She'll be housemate friendly.
Daisy Hookum is a sixth year Ravenclaw and a total space case. She usually has an art project going and tends to be a bit of a slag believing in this free love thing. She's nice to everyone.
Greta Catchlove is a sixth year Hufflepuff and the laziest person in the entire school. She's president of "nap club" and uses that as an excuse to sleep all afternoon and avoid homework. She's too laid back to get into anyone's way.
And finally Emma Vanity, seventh year Gryffindor and muggle born. She's sarcastic and snarky and hates everyone. She'll be snarky at him if he talks to her.