Dai was born as the youngest of three siblings. His mother Maki had the impression that he was an easy child to take care of, but... One spring, his two older brothers got jobs and lived alone, and his father moved away from his family, and Dai and Maki began living together as mother and son. The once lively house suddenly became quiet, and Maki felt a sense of loss... Seeing his mother like that, Dai felt lonely and regretful, and tried to get back the love of his mother that he had never had the chance to monopolize...