Kyousai Usa (宇佐 驚斎, Usa Kyousai) is a senior classman of Hakoniwa Academy and one of the delinquents who originally made up both the Kendo Club and the 2% of the votes that Medaka Kurokami did not receive.
Usa ignores the great majority of school rules, instead hanging out in the kendo hall with his friends. Like the rest of his gang, he smokes. After Medaka's intervention however, he seems to have reformed somewhat, and the passion for kendo he once had has been rekindled.
Usa has black eyes and brown hair. He forgoes the uniform of a student of Hakoniwa Academy, instead wearing an orange track suit along with a gray cap decorated with a black skull and crossbones symbol. He has deep bags under his eyes. He is also seen in his kendo uniform.
Student Council Executive Arc
Usa is hanging out at the Kendo Hall when Medaka and Zenkichi Hitoyoshi arrive. At Mahibi Moji's order, he and the others surround the pair. He is amazed when Medaka manages to confiscate the cigarettes of everyone present before they can react. He does not know what to make of Medaka's posing as she preaches to the group. The next day, the group returns to the kendo hall in uniform, much to Zenkichi's surprise. After Medaka leaves to attend the Student Council Recruitment meeting, the Kendo Club is attacked by Habataki Hyūga, who defeats them all. To Hyūga's shock, Moji gets back up, proclaiming that even he was once passionate about kendo. Inspired, the other members rise back up as well, Usa declaring that he was once aiming to be the greatest swordsman in Japan. An enraged Hyūga attacks them, only to be stopped by Zenkichi. After being "converted" by Medaka, Hyūga takes over the Kendo Club and shares the hall with the other members, though he and Moji sometimes butt heads.
Usa is seen being chastised along with Kenna Yatsushiro, Hisshuu Kanoya, and other members of the Kendo Club by Harigane Onigase of the Public Morals Committee for their improper clothing. Despite her warnings, Usa and his friends brush Onigase off. After Myouri Unzen blows up the Student Council office, Usa and several other members of the Kendo Club hear the commotion, though they assume it is simply Medaka being up to her usual antics.
Kumagawa Incident Arc
At the end of the semester, Usa is present for Medaka's speech. He is surprised by Misogi Kumagawa's sudden entrance, and declaration that he is Medaka's ex. On August fifteenth, Usa is among the students who come to the Vice-President's Battle to cheer for Kuudou Hinokage. On August twenty-second, Usa and other students try to attend the President's Battle to cheer for Medaka, but are unable due to the nature of the match.
Kurokami Medaka's Successor Arc
Unknown Shiranui Arc
Bouquet Toss To The Future Arc
Usa is among the students who confront Medaka at the beginning of the 100 Flowers Run, holding flower number twelve. He and the others are all blown away by Medaka's Kurokami Final. All present wonder if Medaka thinks of their time together as good memories. His message to Medaka is a thank you.