Sumire is a kunoichi of Konohagakure's Scientific Ninja Weapons Team and a former member of Team 15. She was also the Class Representative of Boruto's Class in the Ninja Academy.

Spoiler

While under the guise of "Sumire Kakei", she was a rather meek and quiet girl who, like many children her age, adored the Seventh Hokage. While not very outspoken, Sumire showed genuine concern for her classmates. Sumire was also very respectful and dutiful and wished to avoid conflict if necessary. Her reason for wanting to become a shinobi was to live up to her father's memory. Once dropping the guise of a meek girl, Sumire is shown to be a very driven person, and, due to her arduous training as a child, dedicated to completing her father's final request, showing no remorse for her former friends and other villagers. When confronted by Boruto, Sumire exclaimed that the Sumire he knew never existed. Despite this, she had still come to value the friendship she made with her fellow classmates who in reality did not want to hurt anyone. Thanks to Boruto's unwavering loyalty to her, Sumire was able to let go of her past and answer for her mistakes. She also developed a strong bond with Nue, seeing it as her family. Once returning to her status as class rep, Sumire reverted to her meek attitude. She is also shown to be very methodical and analytical, having quickly understood the nature of her friends' preferred battle tactics and how best to approach them for the Chūnin Exams.

By the time she began working for the Scientific Ninja Weapons Team, Sumire seemed to become more calm and confident about herself, openly expressing herself. She also developed romantic feelings for Boruto, openly saying she was interested in him.