Fragments are individual pieces of human emotion that take on a form similar to flowers. Those with strong enough Fragments can become Reflectors, beings who possess specialized rings that allow them to connect their thoughts, memories, and emotions to others whose feelings may waver. There are two types of Reflectors: those who wear blue rings to protect people from falling into depravity by preserving their Fragments, and those who wear red rings to prevent negative emotions by stealing the Fragments of others who begin to develop severe woe.
Ruka Hanaris is a shy and introverted transfer student who struggles with socializing due to her personality. However, in a chance encounter, she bumps into a woman who drops a blue ring as she rushes away. Unable to return it, Ruka brings it back to her dorm and meets Hiori Hirahara, another person with a blue ring. Together, they face conflicts against red Reflectors and slowly realize the true power of their rings. They strive to become Reflectors themselves in order to save not only those around them but also themselves from emotions that hold them back.