Shirо̄ Sakurai is Shinichi Sakurai's father and Nodoka Sakurai's parent, characterized by dark brown hair, brown eyes, and a physical resemblance to his son Shinichi, particularly their sharp eyes. He typically wears a long-sleeve off-white shirt and off-gray sweatpants.

He maintains a lighthearted, unserious demeanor, lacking traditional paternal authority. His relationship with Shinichi is relaxed and filled with banter rather than sternness. Shirо̄ avoids interfering in his children's lives, preferring to give them space, a contrast to Fujio Uzaki's more involved style. His approach to family life includes scheming for personal goals, such as intentionally limiting contact between Shinichi and his mother to facilitate raising a new child undisturbed.

Shirо̄ runs a martial arts dojo where he teaches jujutsu, indicating his expertise in the discipline. Despite this professional background, his overall easygoing nature means his demeanor is not fierce or intimidating.

He is married to Haruko Sakurai. Their partnership involves collaborative family decisions, though Shirо̄ often initiates plans related to expanding their family. Haruko attributes Shinichi's tendency to prioritize personal desires over others' expectations to Shirо̄'s influence. Shirо̄ and Haruko concealed the pregnancy and birth of Nodoka during Shinichi's prolonged absence at college, revealing her existence only when Shinichi visited home.

His relationship with Shinichi features mutual comfort and joking exchanges, showing no genuine conflict despite initial hints of strain. Shirо̄'s absence of conventional fatherly traits and preference for a carefree lifestyle contribute to his role as a comedic yet affectionate figure within the family.