Rui is a fifteen year old highschool student, who after enduring years of bullying, is brought to the brink of death and left to die in an alleyway. That's when he meets Kana, the mysterious 500 year old vampire who appears almost like a guardian angel.
He saves Rui and turns him into a fledlging vampire. But what seemed like a random act of kindness has turned into a sadistic relationship between master and dog.
Rui now must learn to traverse the vampire world with his seemingly lazy yet dangerous new guardian who shrouds his past in secrets.
Labeled as a Fool, Rui takes it as an insult, but it's actually the name given to vampires from a specific blood attribute. Among the vampire hirearchies structured in Suits like playing cards, Rui is a Fool. A rare and special Suit despited by vampire kind.
Stuck between the boundaries of being a human and a vampire, he must now decide to retain his humanity or accept his new immortality, all while facing the dangers that comes from the shadowed world he was forced to become apart of.