Calix Adrian, Marquis and Chief of Security for the Elak Empire, is also the formidable leader of the 'Vesper' special unit. Following a dark tip, he descends upon a gruesome scene of bloody corpses, only to find Aran Pavel bathed in the light of a pristine full moon, emanating an inexplicable, divine power.

"I hereby name you my sworn protector."

For reasons unknown, Calix finds himself powerless to defy Aran's command. Aran collapses after issuing the decree, only to awaken with his memory of the entire incident wiped clean! Calix, seized by the chaos, exploits the excuse of recovery to confine Aran to his own estate, placing him under constant surveillance.

But the Marquis’s control is soon challenged. One day, a desperate Aran, consumed by a burning, unbearable thirst, throws himself upon Calix.

"Help me, please! This thirst is driving me mad. Marquis, you must kiss me."