Aggressive. Serious. Determined.

To Masumi, life is a constant fight between your will and everyone else's, and it is everyone's own responsibility to fight for themselves. She is a belligerent, strong woman who has endured a great trauma at a very young age, which distorted her worldview and made her become bitter and distrustful. Deep down, she's loyal and tries to be as fair and good to others as possible, while prioritizing her own needs first. Her inability to open up and relate to others without conflict makes her a difficult person to handle, however, and that eventually leads to tragedy.

Her voice should be low, firm, serious and strong. She is open, impatient and proud. A good character reference, weirdly enough, is Bakugou, from BNHA.