Two-year-old Nene and her high school-age sister Tamako live alone in their family home after their parents died in an accident. With no other relatives to rely on, the two manage day by day, but the strain of raising a toddler while still being a student weighs heavily on Tamako. Suddenly, a mysterious young man named Aoi appears and begins to take care of them. His intentions are unclear, and his presence introduces an element of uncertainty into the sisters' fragile daily life. As Aoi gradually becomes a fixture in their household, the story follows the evolving relationship between the three of them, exploring themes of family, trust, and the quiet struggle to build a new normal after loss. The series is a slice-of-life drama that focuses on the small, tender moments of Nene's childhood and Tamako's efforts to balance sisterhood, school, and survival, all while Aoi's role in their lives remains a central question.