|This article is about a/an character in Kamen Rider Build.|
One day, while tending to her farm, Kimiyo had a heart attack and so her grandson took her to a hospital to be treated only to be blocked by Hokuto soldiers. Seeing their plight, Kazumi Sawatari beat up the soldiers and allowed them to proceed. Thanks to his help, Kimiyo was treated in time and made a full recovery.
Becoming indebted to Kazumi, Massugu decided to follow him on his crusade into Touto, to the point of endangering himself by becoming an Ice Smash. However, he was ultimately defeated by Sento Kiryu, who suggested that he would do better to return to Hokuto and continue supporting his grandmother.
Behind the Scenes
Kimiyo Ubukata was portrayed by Kyoko Izumi (和泉 今日子 Izumi Kyoko).