She is a genin from the Konoha village, born as Sumire Shigaraki. He is a descendant of the Shigaraki clan, faithful servants, and believers in the ideal of Danzo. With the fall of Danzo, many families were exposed, including Sumire’s. Due to stress, humiliation, and worry, Sumire’s mother died soon after.
Similarly, it happened with her father, who shared with his daughter, the plan to get revenge on Konoha for having humiliated them; Due to this, he decides to implant the Gozu Tenno in Sumire, which causes his death.
Once an orphan, Sumire decides to change her name to Sumire Kakei and join the Ninja Academy, where she stood out as the first of her kind in everything; Parallel that, he decides to join the Ninja Scientific Tools Team, in which he plays the role of assistant to Katasuke Tono.