Vampeerz, Volume 1: My Peer Vampires (manga)

A death in the family introduces Ichika to Aria, a family associate who may also be a lovely vampire.

Ichika's life has taken a sudden turn. Her grandmother has passed away, so as family and friends come from far and wide to pay their respects, she finds herself in the spotlight as many of these old faces have taken an interest in her youth. As a fourteen-year-old, Ichika could be dating. She could be participating in extra-curricular activities. She could be looking to her future...But she hasn't done any of that. All of that will change when a young guest who she does not recognize visits her home. Aria seems to know quite a bit about her family and property, and while she may be there to say goodbye, she may have found her way into Ichika's heart.