A menace of huge monster-like insects is plaguing the land of Edo. Too powerful to be subdued by ordinary folks, the creatures are hunted by the Insect Magistrates—a group of warriors who specialize in various secret arts and combat styles. To bolster their strength, they summon Genjuurou Tsukishima, the master swordsman from the Tsugaru Province. Due to an unfortunate incident, however, Genjuurou is incapable of answering the call and sends his son, Jinbee, to serve in his stead. Determined to atone for the incident caused by his own cowardice, Jinbee agrees to travel to Edo and join the Insect Magistrates. Armed with his fiery spirit and unwavering resolve, Jinbee vows to become a stronger samurai and rid Edo of the insect threat once and for all.

For generations, the Bernstein family has been recognized as a house of nobles who favor books over everything else. Elianna Bernstein, daughter of a baron of the Sauslind Kingdom, is no different. But instead of being called a bookworm, she is known as the Bibliophile Princess. Four years ago, the crown prince, Christopher Selkirk Asherald, offered Elianna a special arrangement: if she would become his fiancée, he promised that she could continue to spend all her free time reading. Despite having to inherit a title of great responsibility, she agreed to the proposal, enticed by the prospect of gaining access to the royal archives housing a wide selection of books. To this day, Elianna firmly believes that her engagement is void of romantic sentiment. When she notices Christopher's interactions with another girl, she presumes that the days she spends with him will soon reach an end. Yet, during this period of uncertainty, Elianna and Christopher open a new chapter in their relationship, gradually uncovering their genuine feelings as they grow to better understand each other.

OVAs bundled with the 15-17th volumes of the Mushibugyou manga.

The first episode, Musha, Knight, Commando: SD Gundam Emergency Sortie, features the three Gundams and a young girl named Riplin joining together to fight evil. The second episode, Dawn of Papal, Episode 103: Suginamu's Bride, stars Artesia in a fantasy-themed adventure.