Daiichi Yamura was a hard-working and responsible boy despite his gruff "no-nonsense" exterior. He dedicatedly took care of his three younger siblings: Futaba, Santa and Yoshi. He accepted this task because their mother had died much earlier, and their father abandoned them for unknown reasons three years ago. Their uncle on their father's side made up for his brother's disappearance by renting a home for the four siblings to live in, and paying for all expenses. Daichi earned his keep by working as a mail and newspaper boy, and for his uncle's landscaping business on his days off. He chose to live separately from his uncle with his siblings so that his father would have a place to return to if he ever decided to.