Individual fragments of human feeling normally appear as blossoms called "Fragments." Only a small number who hold sufficiently strong Fragments may transform into "Reflectors," beings that wear special rings enabling them to link their thoughts, memories and emotions with those whose feelings are unstable. Reflectors come in two varieties—those donning blue rings who safeguard people slipping into darkness by preserving their own Fragments, and those wearing red rings who counter negative moods by siphoning the Fragments of those beginning to suffer intense sorrow.
Although transfer student Ruka Hanari longs to mingle with classmates, her shy and withdrawn nature constantly hinders her. One fortuitous moment, she collides with a woman who hurriedly drops a blue ring; unable to return it, Ruka keeps the ring and takes it back to her dorm. There she encounters Hiori Hirahara, an extroverted girl who also possesses a blue ring. Together they confront several red Reflectors, gradually discovering the true strength of their own rings.
Now determined to become Reflectors themselves, Ruka and Hiori must cooperate and grow stronger so they can rescue not only those around them but also protect themselves from the emotions that restrain them. Their journey will test their resolve and forge an unbreakable bond.
