The father of Sōma Yukihira, and owner of the diner Yukihira in the Sumire Shopping District. His passion for cooking knows no bounds and his skill is world-class. As the sole parental-figure and family member in Sōma's life, he is a mentor, teacher, and rival to his son. Like Sōma, Jōichirō is laid-back but professional and has a serious side that emerges when he is cooking. The two share the same habit of creating horrible experimental dishes. Jōichirō is supportive of his son but does occasionally like to see Sōma stressed and frustrated by challenging him to many cook-offs – always ending in Jōichirō's victory – to show him how much he has to grow. He left home to work abroad and sent his son to Tōtsuki Academy, telling Sōma that he needs to succeed in Tōtsuki if he ever wants to surpass him.
World-famous as Jōichirō Saiba (才波 城一郎 Saiba Jōichirō), he attended Tōtsuki Academy under this name, a 69th generation student, resident of the Polar Star Dorm, and 2nd seat of the Elite Ten council. Gin Dojima, the 1st seat and Jōichirō's best friend, knows that Jōichirō's cooking skills was far superior, having a record of 20 wins and 101 losses in their cooking matches. The only reason Jōichirō is not the 1st seat is because he is too laid back and care free.
A talented and creative chef, he earned the nickname Asura (literally 'demon') after he single handedly defeated up to 100 opponents in a regimental shokugeki. During the middle of his third year, the pressure of continuously creating new dishes took its toll on Jōichiro. To the point that he skipped B.L.U.E, the world youth cooking championships, in which he was favourite to win. Gin and Senzaemon blamed themselves, and suggested Jōichiro withdrew from the academy and travel the world to learn about cooking on his own terms. Azami, who was two generations behind Jōichirō and wanted to push Jōichirō's skills to fulfill his ideal of "true gourmet", was resentful when Jōichirō left without graduating. Eventually, Jōichiro returned to Japan where he met his wife and opened a family restaurant.
Jōichirō is a close friend of the Nakiri family, often requested by Senzaemon to privately cook for him. On one such occasion, a young Erina curiously followed the aroma of his cooking, and was allowed to join them. Jōichirō's cooking and manner inspired Erina to follow a brighter path as a chef, and this became one bright memory she held onto through Azami's brainwashing. Years later, Jōichirō arrives and coerced Azami to accept an irregular team Shokugeki, betting a lifelong servitude to Azami against Azami and his cohorts' expulsion from the academy. Jōichirō, Senzaemon and Gin then act as coaches, giving special lessons to the rebel students in preparation of the upcoming team match.