The Poe Clan(1972)

The Poe Clan: a race of undead that feeds on the energy of the living, whiling away the centuries in a village of roses where time and geography have no meaning. Circumstances lead to a brother and sister, Edgar and Marybelle, being initiated into the clan too young, and therefore doomed to live out eternity forever on the brink of adulthood, until a wooden stake or a silver bullet should cut them down. In this groundbreaking manga, through three immortal adolescents and the mortals whose lives they touch, Moto Hagio explores what it means to live and to die, to have loved and to have lost.

(Source: Fantagraphics)