In 2012, humanity faces a catastrophic end as a human-made virus wipes out the global population, leaving only children unaffected. At this pivotal moment, ancient vampires rise from the shadows, followed by dark forces that are mere whispers of old horrors. These undead creatures descend on Earth in a single violent assault, subjugating humanity and transporting survivors into underground safety. The "protection" for this newfound power comes at a cost - donating blood to vampire captors. At twelve, Yuichiro and his friend Mikaela hatched a plan to escape the Hyakuya Orphanage with other children. This daring venture led to their demise, but Mikaela's sacrifice allowed Yuichiro to survive. In four years, Yuichiro vowed revenge against vampires for murdering his "family."
One day, a mysterious virus appeared that killed all human adults die, and va...