In a land plagued by giant insects, the people of Edo cry out for aid, leading to the creation of the Insect Magistrate Office. Jinbee Tsukishima, a young man with aspirations of mastering the sword like his father, joins this elite group to redeem himself for a past mistake. Along his path, he encounters Haru, a kind woman running her family's tea house, and must wield his blade to protect her. His valor secures him a place in the Insect Magistrate, where he faces the daunting task of eradicating the insect horde. Can this novice warrior succeed in saving the realm from the insect onslaught?