The main antagonist of the story, though it is found out later in the series. Kasumi strives to destroy all of the trio's efforts, relishing the power of destroying someone's life and making others miserable. Because Nobuko considers Kasumi to be her first friend, nobody suspected her intentions until Shuji found out. Later on, Kasumi learns an important lesson about friendship and redemption, and is given a chance to turn over a new leaf at Nobuko's grace.
