The Boy (2018)

At some point during the main character's thirteen years of life, she apparently realized that she belonged to the feminine gender identity (as implied by her taste for feminine attire and cosmetics) despite being biologically male and having been raised as a boy accordingly. Nobody else seems to have known of this gender identity mismatch until she reveals it at her thirteenth birthday party. Under years of conventional understanding that she has been a boy; her parents, grandparents, uncle and aunt have brought various birthday presents associated primarily with masculine gender roles by society (two of the presents being toys such as dolls of tough male comic book superheroes), and these family members are initially taken aback and bewildered by the revelation of her sentiment and her feminine fashion interests, but they accept and embrace her nevertheless.