Twenty-three-year-old Masamune Kazama spends his days working a mundane office job and dwelling on the past. Although five years have passed, the young bachelor continues to hold onto his relationship with his ex-girlfriend, Youko Tsukamoto. Out of the blue, he receives a call from Youko's mother, who informs him that she has died in an accident. Furthermore, he learns that Youko has left him with a young daughter, who was raised in secrecy overseas. Stricken with grief, Masamune decides to take in the young girl and raise her on his own. My Girl is a tale of family, loss, and acceptance as Masamune navigates the complexities of daily life as a single father.