After the passing of their mother, Tomoe and Mikage have been taking care of each other. Tomoe, the elder sister, is determined to excel in her studies and secure a bright future by getting into a reputed college. However, she is vexed by Mikage's unruly behavior. In the initial pages of the manga, Mikage stealthily clamps a collar around Tomoe's neck, coercing her to wear it throughout the day. Mikage desires undivided attention from Tomoe, raising doubts about her platonic love for her sister. Meanwhile, Mikage has landed herself a new female acquaintance, who happens to have a deep crush on her. Despite attending different schools, the bond between the sisters remains the most significant aspect of their lives.
