Raul and His Vampire Prince Vol 1

From the Seven Seas Entertainment edition

An orphan saved by a deceptively youthful looking vampire finds himself forever devoted to the fanged beauty in this Boys’ Love manga! Once a homeless orphan, Raul was taken in and saved by Rosé, an eternally youthful vampire with a gentle, delicate air. From that day on, Raul dreamed of becoming strong enough to protect the one who gave him a home. Years of dedication and training shape him into a tall, muscular young man—but no matter how much he grows, Rosé still sees the small, vulnerable child he once was. Caught between who he has become and who Rosé remembers, their days unfold in a tender, sugar-sweet life shared between a vampire and a human.

Source: Penguin Random House API