Serafina, a high-level angel who was ordered to sneak into the world, her mission is to prevent the gate of hell from opening. Kyle, a demon disguised as a human, is on a mission to ensure the gates of Hell come to pass. Holy Flame High School is the battlefield where their fates clash.
When light and darkness met in the classroom, they were supposed to be enemies until death, but were forced to join forces due to an unexpected crisis. They made a temporary truce, but in every temptation and side by side, they couldn't help but move towards the taboo boundary.
However, they did not know that this encounter between light and darkness was no accident. An ancient prophecy is quietly coming true: when the hearts of angels and demons beat for each other, the eternal barriers will collapse, and a storm sweeping the three worlds will begin...
