He and Christabel were the same year at school. She was a Hufflepuff, but would have been friends with just about anyone. She academic and intellectual, she is part of a muggle secret society that thinks it can do magic. She goes just to make fun of the muggles. Society talked a bit about her this past year because she was right on the cusp of spinsterhood, married a first born son who pretty immediately was killed and is still around as a ghost.

Merida has a connection to several of the curse breakers on the board - she thinks its a very 'dashing' profession and would have serious sympathy points for him. She is helping a curse breaker at the moment try to recover memories he lost due to a curse item, and could reach out because of that.

Longwei is a year older than him - His family are in that MC cusping UC, his father would like him to marry upwards

Meserimus is at the school too - incredibly old and 'parents' just about everyone, and may periodically, and good naturedly try to pimp his children and grandchildren to him.

Yuri probably thinks he's as cool as all heck, but probably isn't a good enough student to take his class, but does probably look for opportunities to interact with him.

Emma is generally a keen student, under a lot of pressure from her family to hide her academic light under a bushel and marry well, so he might notice disparity in her behavior - where she is academically strong in her written work and in private but doesn't put her hand up much in class.