The manga series centers on a young man named Haruto, who becomes the sole caregiver for his younger sister, Sana, after their parents pass away. Struggling with financial instability and the responsibility of raising Sana, Haruto takes on various part-time jobs to make ends meet. Despite his efforts, providing enough food for his sister becomes a constant challenge, as Sana has an unusually large appetite that far exceeds what their limited budget can afford. This dynamic forms the core of the story, exploring themes of familial love, sacrifice, and perseverance.

Haruto’s determination to ensure Sana never goes hungry drives much of the narrative. He often goes to great lengths, including skipping meals himself or taking on physically demanding work, to secure enough food for her. Sana, while aware of her brother’s struggles, remains a cheerful and optimistic character, often expressing gratitude for his efforts. Her boundless appetite becomes a recurring source of humor and tension, as Haruto must constantly find creative solutions to satisfy her hunger.

The series also introduces a supporting cast of characters who influence Haruto and Sana’s lives. These include coworkers, neighbors, and classmates who provide assistance, advice, or occasional challenges. Some characters offer Haruto job opportunities, while others become friends who help him navigate the difficulties of balancing work, school, and caregiving. The interactions with these characters add depth to the story, highlighting the importance of community and support in overcoming adversity.

Throughout the series, the bond between Haruto and Sana is a central focus. Their relationship is portrayed as deeply affectionate, with Haruto’s unwavering dedication to his sister serving as a testament to his love and resilience. The narrative balances moments of lighthearted humor with poignant reflections on the struggles of poverty and the sacrifices required to care for a loved one. The story progresses through a series of episodic challenges, each resolved through Haruto’s resourcefulness and determination, while also subtly building toward a broader exploration of their future and the possibility of a more stable life.