Just by touch, Umbra can steal good luck from people, while her twin Antumbra gives bad luck. So long as they are together, their abilities cancel each other out, so neither knows of her power until they go to different universities. There, things became ridiculously easy for Umbra, while Antumbra lived the life of an outcast. Antumbra can only live a normal life if she's near her sister, but Umbra has been using her power to gain fame and fortune and wants nothing to do with her twin. With the help of a mysterious stranger, Antumbra fights to regain her sister's love and fix the balance of luck in the universe.