The declining birth rate in Japan has led to a significant decrease in the sparkly innocence of human children, a vital energy source for the magical world. With businesses closing due to the shortage, a resolution is passed: a lasting romance will be created for humans who prioritize their hobbies or careers over falling in love. Before this policy is enforced nationwide, the magical fairy Riri selects high school student Anzu Hoshino as a preliminary test subject. Primarily preoccupied with her video games, beloved pet cat, and her obsession with chocolate, Anzu is the perfect candidate. Unfortunately for Riri, Anzu is vehemently against this idea and actively works to thwart the magical world's vain attempts at forcing her into a romance. Even with her distractions confiscated, Anzu stubbornly tries to evade her new predetermined fate, only for it to backfire when she collides with Tsukasa Kazuki, a hot guy from her school. Now unable to avoid the boy she had not even noticed before, Anzu wonders if her sabotage tactics will prove to be futile. [Written by MAL Rewrite]

Romantic Killer began as a web comic submitted to LINE Manga Indies and other sites before official serialization began on Jump+ on July 30, 2019, after winning the Grand Prize at the second Jump Vertical Scrolling Award. The series was published in English by VIZ Media under the Shojo Beat imprint from October 4, 2022, to July 4, 2023.