Reference for the voice can be heard here!

Toko is intellectually gifted, yet she has problems in social behavior. It's been stated that she either never learned or never bothered to learn social skills. She even considers herself a 'gloomy outcast', often deciding to distance herself from others. Due to the constant bullying she faced as a child, Toko is highly suspicious of other people, frequently accusing them of thinking bad things about her. She expresses her opinions freely and extremely, which can come across as mean and often rubs people the wrong way, though she claims she is just being honest.