Luna

Luna follows the life of sixteen-year-old Regan as she keeps the secret of her older sister Luna's transgender identity. During the day, Luna pretends to be an average senior boy named Liam. But at night, Luna is allowed to be her true self: Lia Marie, a girl. Later, she changes her female name to Luna, which means "moon", to reflect that her true identity could only be seen at night. After years of ‘transforming’ only at night, Luna confides in her sister that she wants to transition into a full-time female. Luna asks Regan to help her with her transitioning and, although she agrees, she finds herself worried about Luna and her safety. The novel follows Regan as she makes sense of her sister's decision.
Other problems arise for Regan as she is attending high school. She spends most of her life avoiding other students, in fear of letting the secret slip. But a new boy at school, Chris, becomes interested in her. Although Regan enjoys attention from Chris, she draws away from him, choosing to stay focused on Luna.
As Luna is coming out more, her father starts to notice differences in his child and tries to push a more masculine role onto Luna. Regan's father confides in her that he believes Luna is gay. Meanwhile, their mother remains oblivious to the rising tension in the household. Consumed by the workload of her wedding planning business, the mother is constantly out of the house and distant from her family.
Despite the tensions and the negativity weighing on her choice, Luna fights for her right to be the person she feels that she was meant to be. Alongside her, Regan learns to stand her ground, to think more of herself, and discovers the person she wants to be.