A swordsman named Tatsumi travels to the Capital in hopes of raising money for his impoverished village. After he is robbed by a blonde girl in a tavern, he is forced to sleep in the streets, but he is soon invited by a rich girl named Aria to stay at her manor. While waiting for his best friends, Sayo and Ieyasu, to arrive at the Capital, Tatsumi learns of Night Raid, a group of assassins known to attack at night. Come nightfall, Night Raid appears at the manor and kills Aria's guards and parents. During this time, Tatsumi shields Aria while facing off against Night Raid member Akame, only to be interrupted by Night Raid member Leone, the blonde girl from the tavern. Leone reveals to Tatsumi that Aria and her parents have tortured several people from the countryside, including Sayo and Ieyasu. With Sayo already dead, Tatsumi kills Aria without hesitation or mercy, just before Ieyasu dies. Leone invites Tatsumi to join Night Raid against his will.

Leone takes Tatsumi to the hideout of Night Raid and introduces him to the other members, all of whom Tatsumi views as freaks. Night Raid leader Najenda convinces Tatsumi to join Night Raid, since it is their mission to overthrow the Empire and to set up a new democratic government in its place. Najenda assigns Akame to train Tatsumi, but Tatsumi ends up merely cooking and fishing. Tatsumi is later given the assignment to assassinate the corrupt captain of the Imperial Police named Ogre, who often framed innocent people as criminals. At night, Tatsumi finds Ogre in the streets, where they draw swords at each other. When Ogre becomes arrogant, Tatsumi kills Ogre with the slash of his sword. As a cocky Tatsumi reports back to the hideout, Akame does a strip search on him, making sure he was not wounded. Since he has survived thus far, she accepts him as a member of Night Raid.