From Aerandria Scans:
Rinko is an ordinary girl who was born with a mysterious birthmark on her left arm. But when that mark starts to get darker, strange accidents begin to happen everywhere around her, involving even the people she cares about. What will the powerful magic awakening inside Rinko bring her?
In 1987, Purple Eyes in the Dark was awarded the Shogakukan Manga Award for the shoujo manga category.