Makio Kōdai is a reclusive 35-year-old novelist living alone when her estranged sister and brother-in-law die in a car accident, leaving behind 15-year-old Asa Takumi. Despite their strained relationship and lack of contact, Makio becomes Asa's guardian. The two struggle to adjust to living together—Makio uncomfortable with family bonds and Asa grieving her parents. Through daily challenges, Asa begins journaling her thoughts and feelings, while Makio gradually learns to open her heart. Together, they navigate loss, growth, and the meaning of family in this tender story of healing.