In a world where nearly every child is born with an Iris, an eye-based power that overlays useful information onto reality, Toru Mizushima is one of the rare few with none at all. To survive school without being singled out, he lives by a rule of minimal exposure, staying invisible and uninvolved. That cover cracks when Koyuki Sasamori, the most admired girl in school, confesses to him in front of everyone, forcing the Iris-less boy to rely on plain observation and reasoning where his classmates lean on their powers.