Ken Sudō is a student of class 2-D and a member of the Basketball Club. Due to his poor academic ability, he is referred to as one of the 3 Idiots of D-Class. Regardless of this, his athletic ability is without a doubt one of the best among the school. Ken puts very little efforts into his studies, which grants him the nickname with two other classmates the "3 Idiots of D-Class". He is always seen to sleep in class, and also once refused to join Suzune Horikita's study group for the sake of his grade. He is known to be hot tempered, and quick to anger when people do what he deems to be pointless or insulting to him, showing how easily provoked he can be. When others attempted to help by stopping him, he exclaimed how he doesn’t need their help and would get angry at the person who he deems is underestimating him. Despite his perceived eagerness for a fight, he is shown to get easily scared whenever he is overpowered as shown in his confrontation with Kakeru Ryūen.