Ryousuke Kirishima

As a child, his parents abandoned him and he was raised at the Hidamari Garden Children's Nursing Home. There, he became fast friends with fellow orphan Haru, often defending her when others made her cry. With a strong sense of justice, he believed in never ignoring someone who needed help.

He is Bossun and Tsubaki's biological father. He was killed on the day of his sons' birth when he jumped in front of a car to protect a young Taisuke, who had been playing in the street.