"Papa no Iu Koto o Kikinasai!" centers around Yuuta Segawa, a 19-year-old college student whose life takes an unexpected turn when his older sister and her husband, a researcher, go missing during an overseas trip. Left in charge of their three young daughters—Sora, Miu, and Hina—Yuuta must navigate the challenges of suddenly becoming a guardian while balancing his studies and personal life. The series explores the dynamics of this makeshift family as Yuuta steps into a parental role, learning to care for the girls and manage their emotional needs.

Sora, the eldest at 14, is mature and responsible but struggles with her own insecurities and the weight of her new responsibilities. Miu, 10, is energetic and mischievous, often causing trouble but also bringing levity to the household. Hina, the youngest at 3, is adorable and innocent, requiring constant care and attention. The narrative delves into the daily lives of the characters, highlighting their growth and the bonds they form as they adapt to their new circumstances.

The story also introduces Raika Oda, Yuuta’s childhood friend and neighbor, who becomes a source of support and occasional comic relief. Her interactions with Yuuta and the girls add depth to the family dynamics. Additionally, the series touches on themes of responsibility, resilience, and the importance of family, as Yuuta and the girls navigate their shared challenges and learn to rely on one another. The blend of heartfelt moments, lighthearted humor, and occasional drama creates a balanced narrative that captures the complexities of their situation.