Joujuu Senjin!! Mushibugyou OVA
As giant insects lay waste to the land of Edo, the Insect Magistrate Office gathers powerful warriors to defend the populace from the invading threat. A rookie swordsman named Jinbee Tsukishima seeks to atone for past sins by joining their ranks, but he’ll need to prove his worth if he wants to find redemption and curb the insect infestation.
[Source: Sentai Filmworks]