Undefeated Bahamut Chronicle is a series of light novels written by Senri Akatsuki and illustrated by Ayumu Kasuga. The television series, directed by Masaomi Ando and co-produced by animation studios Lerche and Orange, aired from 11 January to 28 March 2016. The opening theme is "Hiryuu no Kishi" by TRUE and the ending theme is "Lime Tree" by Nano.Ripe.
Lux, a former ruler of an empire called Arcadia that was overthrown by a rebellion five years ago, accidentally transfer a female dormitory bathroom area, seeing the new princess naked Lisesharte empire, causing bother. Lisesharte challenges Lux Drag-Ride a duel. Lux was formerly called the Drag-Knight stronger, but now is known as the "weakest invincible" Drag-Knight because he absolutely does not attack in battle. After his duel with Lisesharte, Lux ends attending the academy just for girls coaching royalty to be Drag-Knights.