Yumi awakens in heaven. But a dark sea tries to swallow her and pull her into unfathomable depths. At the command of Archangel Gabriel, Yumi must interrupt her training, return to Earth, and live among humans from then on. Desperate, she searches for a way back. Taen, disobedient and wild, drives not only the inhabitants of hell but also Lucifer himself to the brink of fury. After a prank gone wrong, the angry lord of hell banishes him to Earth. Taen must prove himself as Lucifer's eyes and ears if he doesn't want to spend his existence as a powerless human until the Day of Judgment. Arch-enemies since the beginning of time, angels and devils meet in human form... and fall in love. Enraged, Gabriel stands between the lovers with all his heavenly power.