After six millennia of bitter warfare and strife between Heaven and Hell, the two realms finally agree to sign a formal peace treaty.
As the first step toward peaceful coexistence, Heaven dispatches its chief archangel Gabriel — affectionately known as Gal — to Hell Academy as an exchange student. Azazel, a high-ranking demon, is assigned to serve as his guide and handler during his stay.
When a rigid, rule-abiding angel with a saintly aura and an endearingly oblivious streak crosses paths with the academy’s rebellious, sharp-tongued demon heartthrob who hides a soft, sweet side beneath his tough exterior, their clashing cultures, beliefs and daily habits spark a string of absurd, side-splitting misadventures all across campus.
Amid their chaotic, uproarious day-to-day lives, the two gradually grow closer. Together, they foil a sabotage plot orchestrated by the conservative demon faction, and a fiery, cross-species romance blooms between them.
When his one-month exchange program draws to a close, Gal returns to Heaven with great reluctance, unaware that the second phase of the Peace Treaty is already underway. This time, it is the demon’s turn to cross the divide, journeying to Heaven to find the angel who belongs only to him.
