Yukino, Tsukino and Kano's parents. They met as children and married just out of high school, a continuous source of consternation for Miyako's father. Hiroyuki also dislikes his father-in-law, grumbling that the old fool couldn't let go of his daughter. Hiroyuki was an orphan who was raised by his grandfather, and values family very highly, a feeling that Miyako shares with him. He loves his three daughters very much, and is frequently wearing a t-shirt that says "Daughter Love." (His daughters, on the other hand, frequently tease him or treat him a little rudely. E.g., "Shut up, Dad!")
Perhaps due to their relative youth (Yukino was born very soon after they married), Hiroyuki and Miyako are easygoing and silly parents. When Yukino gets into trouble at school for dating Arima, instead of becoming upset with Yukino, Hiroyuki and Miyako are eager to go to school and tell the teachers off and "fight for love." And rather than pressuring Yukino to excel in school like other parents would, they have complete faith in her ability to make her own decisions in life.