Rubén is the youngest son of Miriam and Arón Singman, owners of the huge clothing store Singman Modas: Elegant and Sport. Everything seems to be going well in this Jewish family until this confused young man, who is about to turn 13 and, therefore, the ritual and celebration of his Bar Mitzvah is approaching, decides to tell them that he does not identify as a boy anymore, and that she wants to have a Bat Mitzvah (the female variant of a Bar Mitzvah ceremony). Years pass, and Rubén is now Mumy, who has become a Yiddish singing sensation. She returns to Buenos Aires after a long stay in Spain, now accompanied by her boyfriend Sergio, to perform at the San Martín Theatre. She will meet her mother again, who has always been more accepting of her changes; while the relationship with her more conservative father has always been strained. She also reconnects with her older brother Eduardo, a father of two who is in the process of divorcing his wife Sandra. Mumy will now surprise his family with another peculiar decision: to have her longtime postponed Bat Mitzvah ceremony.