In order to increase birth rates, Japan implements a capability calculation that assigns partners to young people when they turn 16. Those who deviate from their assigned partners are severely punished. Yukari Nejima has been in love with Misaki Tazaki since grade school, and finally confesses to her on his 16th birthday, only to find out he has been assigned to Ririna Sanada. Originally not thrilled, Ririna agrees to allow Yukari and Misaki to continue their illicit relationship in hopes of learning more about love. Things get complicated when Love and Lies start to intersect.