Food Wars! follows the adventures of Sōma Yukihira, a boy who grew up working in his family diner with his father. He soon joins a prestigious culinary school, of which his father is also an alum unbeknownst to him. Armed with his home-style cooking, hands-on work experience, and practical thinking, Sōma participates in battles known as Food Wars against other talented students as a means of creating, learning, and engaging in fierce competition.
Tamako Yukihira was born into a family in the food industry. Her father, Kazusato Yukihira, was a diner cook and the family owned a restaurant. As a young girl, she was rebellious and mischievous until she left high school. Tamako was a notoriously atrocious cook, trying to cook anything and everything. Although the result of this was winning dishes from her now and then due to trial and error.
Tamako met Jōichirō, Soma's father, while he was traveling and came across her family's establishment, noticing that they were struggling to deliver on their customers' orders. Jōichirō then offered his service to Kazusato. The two did not like each other initially. On one hand, Jōichirō found Tamako's cooking to be horrendous; and on the other hand, Jōichirō's constant presence at their restaurant greatly irritated her.
Soon, the two grew closer. Tamako recognized Jōichirō's great skill as a chef and Jōichirō was touched by Tamako's kindness towards her customers. It appears that Tamako and Jōichirō share a love for family and food. They married, ran a family diner together as a couple, and soon had a son; Sōma.
Sōma and his mother share many similarities. Physically, they look very similar with short spiky hair. They are both cheeky, mischievous, and quite the hell-raisers. Sōma's infamous disgusting octopus concoctions seemingly stem from his mother, as she too fed her customers gross octopus experiments.
He definitely shares his mother's confidence and love for experimentation. She has a fighting spirit that never gives up on a dish, as does Sōma. In season 5, fans see a flashback of Sōma remembering his mother. As a little boy, he remembers that he loved watching her cook because of all the fun she had while doing it. In fact, the whole family shares a love of food and experimentation.
One day at Restaurant Yukihira, Tamako suddenly fell in the kitchen unconscious, grabbing her chest. A twelve-year-old Sōma found her and he and Jōichirō took her to the hospital. The cause of this was confirmed to be a congenital heart valve defect. Two months later, she passed away due to complications as a result of this defect.
In the flashback moment in season 5 of the anime, Jōichirō is clearly still smitten with his wife even after years of marriage. After her death, he was lost and depressed, which Sōma noticed. As a way to get his father to regain even a sliver of joy again and perhaps as a refusal to wallow in grief, Sōma challenged his father to a food war, and they had been having food wars ever since. Not only is this their way of honing their skills, but also a means of keeping Tamako's sparkling spirit alive.