Yan Xu

Yan Xu arrives in the world of Heartstopper as one of the wider circle around the show's central friend group, glimpsed at school and in the ordinary rhythms of teenage life rather than at its center. She is watchful, self-contained, and easy to underestimate at first meeting.

Momo Yeung brings a quiet precision to a role that could easily be background noise, giving small reactions real weight. The character works because the show trusts restraint, letting a look or a pause carry as much as dialogue, and Yeung makes those quiet beats count.