"Daddy na Hibi ni..." centers on the life of a young girl named Chiharu, who lives with her father, a single parent. One morning, Chiharu wakes up to find her father has mysteriously transformed into a young boy, resembling a child her own age. Despite his physical change, he retains his adult mind and memories, continuing to care for Chiharu as her father. The series explores their daily lives as they navigate this unusual situation, blending slice-of-life moments with lighthearted humor and occasional emotional depth.

Chiharu, a responsible and mature child, adapts quickly to her father’s new form, often taking on a more protective role despite her young age. Her father, now in a child’s body, struggles with the challenges of being perceived as a peer rather than a parent, while still striving to fulfill his parental duties. Their interactions highlight the bond between them, as well as the comedic and sometimes awkward situations that arise from their reversed roles.

The narrative delves into themes of family, responsibility, and the complexities of parent-child relationships. The father’s transformation serves as a catalyst for exploring how love and care transcend physical appearances, emphasizing the emotional connection between the two. Supporting characters, such as neighbors, friends, and schoolmates, occasionally appear, adding variety to the story and further complicating the father’s efforts to maintain his identity.

The tone remains predominantly light and humorous, with occasional poignant moments that underscore the challenges of their unique circumstances. The series balances its fantastical premise with relatable, everyday scenarios, creating a narrative that is both whimsical and grounded in the realities of familial love and duty.