Thirteen years ago, a devastating plane crash killed almost all of its passengers. Miraculously, Megumi Miyashita survived, but after this incident, she developed a strange power in her left eye. For every one person, Megumi sees two, and when an individual is lying, the double speaks the truth.

In high school, Megumi is a quiet and shy girl whose best friend happens to be Ayaka Mitani—an upbeat member of the basketball team. When the school gains an inquisitive new science teacher, Shouhei Suzuki, he quickly becomes popular due to his youth and bachelor status.

Without notice, the normally indomitable Ayaka stops attending school under the excuse of a cold. However, she won't return any texts, and her mother is tight-lipped, causing Megumi to become increasingly concerned. While she seeks the truth behind her missing friend, Shouhei seems to have developed a personal interest in Megumi.