When 14-year-old middle-schooler Tsugumi Harudori discovers she is a weapon, she flies to America to enroll at DWMA. There, she meets the absent-minded Meme Tatane and the patrician Anya Hepburn, both of whom are meisters that are also new enrollees.

Akane and Clay report to Sid that they suspect the culprit behind the Traitor incidents to be a witch named Shaula Gorgon. Meanwhile, Tsugumi and the others get together for a study session at Deathbucks, helping out when the place gets busier, even if only for a brief moment.

Having spread out Traitors across Death City, Shaula unleashes her magic, making the Traitors more powerful whilst also ordering some of them to kill themselves as she sees fit. Shaula then sends Meme to kill Tsugumi and Anya, with Anya attempting to subdue her to give Tsugumi the chance to administer the antidote.