Oudo Miyakonojou is a senior of Class 13 and is a member of the Flask Plan's Thirteen Party. Oudo is the chief antagonist of the Flask Plan Arc.

Between the ages of six and twelve, Oudo lived alone on the streets. By that point, he had already started considering himself a king. Oudo abandoned his parents because he was worried what they would do they found out about his Abnormality. He lived on the streets for seven years, looked after by the local police, trying to master his ability and not let it take control of him. He thought of mastering his ability as a test to see if he was capable of being king. At the end of those seven years, he was chosen as a representative to speak to the freshmen body of the middle school he was attending. Though he meant to tell the students to live life to the fullest, the first words that came out of his mouth was the order to bow before him. Oudo realized that in seven years, he had never once gained control of his ability; instead, he was the one being controlled. After three years, Oudo enrolled in Hakoniwa Academy. There isn't a soul alive who knows what he did in those three years. As a part of the Flask Plan, Oudo was paired with Maguro Kurokami, who was fascinated by Oudo's abilities. Sometime after Maguro left the Flask Plan, Oudo approached Mizou Yukuhashi, and ordered his fellow student to read his mind. Because Oudo's Abnormality cancelled out Yukuhashi's, the two became partners from then onwards.

(Source: Medaka Box Wiki)