A middleschooler at an unnamed school, she sits at the back of class 1-2 next to Nishikata. Academically talented and physically capable she claims her only weaknesses are her ticklish armpits and her inability to stop teasing Nishikata.

From when she first met him, during the first class of the day of the school's entrance ceremony she has spent much of their time together pranking him, teasing him and challenging him to unbeatable games.

She seems entirely in control of her emotions and every situation she is in, contrasting starkly with Nishikata. Beyond her academic and teasing talents she has the uncanny ability to guess exactly what Nishikata is thinking, so long as she doesn't try to embarrass him by suggesting that he was dreaming up something dirty and can make a silly face which inspires instant laughter in everyone who has seen it.