In Romantic Killer, Anzu Hoshino wants only three things in life: video games, chocolate, and her beloved cat. Unlike other high school girls, she has no time for, or interest in, romance. That stance collapses when she starts a poorly programmed 3D otome game and a bizarre flying wizard named Riri bursts out of the screen, declaring Anzu “subject one,” the first person forced into a dating-game harem storyline in real life.
Riri confiscates Anzu’s favorite things to push her toward love, then engineers a string of unlucky incidents and familiar romantic clichés that bring her face to face with Tsukasa Kazuki, one of the most attractive boys in her school. Anzu is determined to resist Tsukasa’s charm, but the more she is dragged through absurd fabricated scenarios, the more she begins to notice his genuinely pleasant nature. When Riri keeps sending other stereotypical pretty boys her way, avoiding romance becomes almost impossible, and Anzu is left fighting a script she never asked to enter.