Sky High is a thrilling story about a serial-murderer who is removing his victims' hearts and taking them with him. Kanzaki is a detective on the case, determined to catch the killer.
However, tragedy strikes when on the day he is due to be married, his fiancé, Mina, is killed in the same brutal manner as the other victims. Kanzaki is devastated by the loss of his beloved.
As he delves deeper into the investigation, he discovers that a geneticist named Kudo and his evil "secretary" Rei are the ones behind the murders. They have a sinister plan - to collect six hearts in order to summon demons from beyond the 'Gate of Rage' to grant any wish, but at a great cost to the world.
Mina unexpectedly becomes the Guardian of the Gate of Rage, and must confront Kudo when he is killed. In a desperate attempt to protect her, Kanzaki enters the world of the dead to aid her in the battle against evil.