Megumi Tano

Kabuto is a tengu who has to save a princess from fortress which is full of monster-mecha hybrids in an alternate reality of feudal Japan. (myanimelist.net)

500 years ago in the Tensho Era of Japan, a man was born who defied the will of a demon; a man who had gods of good on his side; a man destined to battle evil....his name was Kabuto. Somehow, Kuroyasya Douki, the vile Black Night Demon, escaped his prison in hell and returned to the earthly plane to wreak vengeance on the family-line of Kabuto. (myanimelist.net)

In a cone-shaped land named Kikyōgahara in Shin Province, there lives a girl named Hana. She is a gentle girl, who always thinks of her family, in particular her great-grandmother Chiyo, whom she affectionately calls "Granny." One day, a traveling entertainment troupe named the Natsugawa Genzaemon Troupe happens, and the villagers welcome them warmly. Upon finishing their performance and receiving their acclaim, the troupe's leader spots Hana with some "oyaki," his favorite food...

The OVA tells the story of Laethreel (or just plain Lath), a wannabe demon-breaker who controls a powerful sword, Gurenki, but not much else. She suddenly acquires a “protector”, Anshu, and a mission: to rescue the kidnapped princess of Gandia from the clutches of the jet-black demon Aju. However, Laethreel shares a dark secret with her younger brother Leedyle, and her mission proves more complicated, and dangerous than it first appears.