The series originated as a short film of the same title which aired in 2017. The miniseries retells elements of the short film. The series was filmed in Adelaide, South Australia including on location at Marryatville High School.
The series is about twelve year old transgender girl, Hannah Bradford, as she adjusts to high school at the start of a new year. She must navigates the social and personal issues of her early teenage years, while also dealing with the pressures of her gender identity, which is largely private at the beginning of the series. Overriding themes include the focus on identity and belonging, and the exploration of transgender rights.
First Day and the associated short film have received a positive reception for its representation of diversity in transgender children. The short film won an award for diversity from MIPCOM and won a Prix Jeunesse Gender Equity Prize in 2018.