In this world, people are born without a gender. Then, children's bodies shift toward their desired gender when they reach twelve years old. Until Hinase's eighteenth spring, they lived content without a gender. But bubbly girl Ritsu and thoughtful boy Shiori both confess their feelings on the same day! Romance was never on Hinase's mind, so how can they respond? Hinase must explore their identity as they arrive at the cusp of adulthood.