Vampire and Hunter

Long ago, a young boy named Libra Brian wandered into the vampire Lasombra's castle and became smitten, swearing that one day he would marry him. Libra grew up to become a vampire hunter, but his love for Lasombra never faded and the two eventually become lovers. Hundreds of years later, the vampire awakens from a long sleep to find his human paramour still alive, but to Libra's dismay, Lasombra has lost all memories of the love they once shared, and the vampire now believes his long-time human companion is actually an enemy plotting to kill him! How can Libra rekindle their romance and help his amnesiac lover learn to navigate the modern world when every move he makes is considered a plot to destroy him?