After witnessing the brutal murder of his parents at a tender age, Ken vows to track down the perpetrator with the piercing red eyes and exact revenge. On his journey, he discovers a mysterious system that reveals his true identity as a Demigod-Vampire. To grow stronger, Ken must complete quests and missions, but he's faced with an impossible task: consuming blood. Ken's aversion to blood makes this quest seem difficult, as he faints at the mere sight of his own blood. As Ken delves deeper, he uncovers a shocking truth - the killer is a family member, also a vampire, implying that one of his parents was a vampire and the other a demigod. Armed with this knowledge and the guidance of the system, Ken sets out to unravel the mysteries surrounding his parents' tragic deaths and confront the darkness within his own family.