Heigo Irino owns Ryokushō, a traditional wagashi store in Kyoto, projecting a reserved and traditional demeanor especially concerning shop succession and family duty. He possesses black eyes and gray hair with male pattern baldness, consistently wearing a plain white chef outfit appropriate for his role.

He is the husband of Fuki Irino and father of Nagomu Irino. Heigo is also the grandson-in-law of Masayo Irino and the son-in-law of the deceased Ikkō Irino. His given name, Heigo, combines the characters for "peaceful" (平) and "samurai/file" (伍); his surname, Irino, originates from "settlement/payment" (納) and "field/wilderness" (野).

His parenting approach surfaces in the strained relationship with his son Nagomu, who left home for a decade pursuing music. This departure forced Heigo to explore alternative succession plans for Ryokushō. Upon Nagomu's return, prompted by a false report of Heigo's hospitalization, he directly challenges his son's readiness to inherit. During Nagomu's absence, Heigo and Fuki took in Itsuka Yukihira, a young girl abandoned by her father. Recognizing Itsuka's dedication and skill, Heigo designated her as Ryokushō's intended successor, establishing a rivalry between her and Nagomu. This decision highlights his prioritization of the shop's legacy and traditional values over bloodline inheritance.

Documented interactions consistently reflect his traditional expectations and measured authority within both household and workplace settings.