Rokuhara Souta discovers a peculiar phone containing the "Friendship System" and connects with an online companion known as Tokisaki Kurumi. Her elaborate roleplay as the fictional Kurumi character proves so authentic that Souta questions reality itself, though he dismisses it as devoted fan performance. Entertained by her commitment, Souta engages freely with the mysterious girl, exchanging witty banter and playful flirtation without hesitation. What could be the harm in amusing himself with a dedicated chūnibyō lost in her fantasy world? His casual attitude shatters when Kurumi extends an unexpected invitation to meet face-to-face. The moment arrives—and Souta's existence fractures across worlds. He awakens in a desolate alley drenched in crimson, severed bodies littering the surroundings, the metallic reek of death choking the air. Before him stands Tokisaki Kurumi, blood still fresh on her hands, offering that same sweet smile as she regards him with unsettling tenderness… The harem awaits across the multiverse: Tokisaki Kurumi, Oshino Shinobu, the Military Princess from Re:Creator, Kamado Nezuko, Ereshkigal, Leticia, and countless others beckoning from worlds beyond imagination.