In a world of magic and monsters, Krylancelo Finrandi and his foster sister Azalie Cait-Sith were once promising students of sorcery, prodigies at the famous Tower of Fangs. But an experiment gone horribly wrong warps Azalie's appearance, trapping her in the form of a dragon. Elders at the Tower—more interested in preserving their reputation rather than their students' lives—drive off the transformed Azalie and cover up the incident. Outraged, Krylancelo strikes out on his own, taking the new name of "Orphen" and vowing to return Azalie to her normal state. Five years later, Orphen's quest has stalled. A chance encounter brings him face to face with Azalie again, but he still has no way to restore her body. And with a hostile group of sorcerers hunting her down, he may be running out of time. The past and present collide as Orphen tries to find how to save Azalie from their former teachers and friends. [Written by MAL Rewrite]

This series was made to commemorate the 25th anniversary of the light novels it was based on. Yoshinobu Akita began the books in 1994. The first season adapts contents from volumes 1, 4, 5 and 6 from the light novels.