Medaka Kurokami is the female protagonist of the series Medaka Box. A freshman of Class 13, she was the ninety-eighth and later ninety-nineth Student Council president of Hakoniwa Academy. She is a childhood friend of Zenkichi Hitoyoshi, who she strong-arms into joining the Student Council at the start of the series. After becoming the head of the Kurokami Group, Medaka also becomes the chairwoman of Hakoniwa Academy. She is the child of Kajiki Kurokami and Hato Tsurubami, and the younger sister of Kujira Kurokami and Maguro Kurokami.
Medaka's biological mother died from a heart attack immediately after childbirth; members of the Kurokami Group coldly said Hato existed only to give birth to Medaka. Because of her abnormal abilities, she quickly matured, and soon was surpassing even adults in all fields. While her growth was initially viewed as fascinating, many professors would retire after seeing their lifelong efforts easily outdone by a little girl, and gradually started viewing her as unsettling instead. Because of this, Medaka began to wonder why she was even born. At the age of two, Medaka was sent to Hakoniwa General Hospital, which studied atypical children; it was a starting point for the Flask Plan. While waiting to get checked, Medaka ended up sitting beside a four-year-old Misogi Kumagawa. He was sorely unimpressed by what was going on, telling Medaka that people are born for no reason. As he was called in, Kumagawa left Medaka with the parting words that there was no point in being alive. These words left a strong impact on Medaka, and she lost interest in the world. Eventually, she grew bored with the constant examinations and tried to escape. Hiding from the hospital staff, she made her way into a nursery room for children of the doctors on call. Inside, she found only one other child, a two-year-old Zenkichi struggling with a toy puzzle. Not knowing how else to introduce herself, Medaka took the toy away from him and easily solved it herself. An impressed Zenkichi asked her to solve the rest of the puzzles in the room, which she accomplished without trouble, much to Zenkichi's delight. Medaka brushed him off, insisting that life has no meaning. When Zenkichi refuted her, she asked him for what reason she was born. He then pointed out how happy she had made him, and told her: "I'm sure you were born to make the people around you happy." Medaka took these words to heart, and the two became friends from that point onwards.
In the Legacy of Chris Thorndyke, She is a member of the Council of Light and got recruited by Amaterasu, when she explored the school in human form and sees her power in action which she was amazed on how powerful she is.
And she is reprised by Shelley-Calene Black in the English dub and Aki Toyosaki in the Japanese dub.