Hi Bye, Mama! includes a subplot featuring a young child, Jang Pil-seung, who identifies as a girl despite being assigned male at birth. The series explores the parents' initial struggles and eventual acceptance of their child's gender identity. The narrative ultimately portrays the child with dignity and frames external challenges as societal misunderstandings, affirming the worth of her self-expression.

The series highlights the enduring power of maternal love and sacrifice, portraying a blended family's journey through grief and reconnection while affirming the fundamental importance of family bonds and parental devotion.

The drama's central premise of a 49-day reincarnation trial is rooted in East Asian Buddhist concepts of the intermediate state. The narrative respectfully integrates this spiritual framework as a foundational element of its fantasy world, presenting the system as a natural part of the spiritual order.