Individual pieces of human emotion typically manifest as flowers called "Fragments." A select few with sufficiently strong Fragments can become "Reflectors," beings who equip specialized rings that enable them to link their thoughts, memories, and emotions with those whose feelings are wavering. There are two kinds of Reflectors: those wearing blue rings to protect individuals falling into depravity by preserving their Fragments, and those wearing red rings to prevent negative emotions by stealing the Fragments of people beginning to experience severe woe. Although transfer student Ruka Hanari wishes to socialize with those around her, her shy and introverted nature consistently hinders her. During a chance encounter, she collides with a woman who drops a blue ring while hurrying away. Unable to return it, Ruka takes it back to her dorm. There, she meets the outgoing Hiori Hirahara, who also possesses a blue ring. They find themselves engaged in several conflicts against red Reflectors, gradually realizing the true power of the rings they hold. Now aiming to become Reflectors themselves, Ruka and Hiori must learn to cooperate and grow stronger so they can save not only the people around them but also themselves from the emotions that hold them back.