Kurokami Medaka, a first year, is elected as Student Council President, and the first thing she does is establish a suggestion box. Since she was just elected as Student Council President, she's holding all the Student Council's responsibilities, and wearing their armbands. So she asks for her childhood friend, Hitoyoshi Zenkichi, for help.
After filtering through the suggestions, which were mostly ridiculous complaints or congratulations on becoming president, they find out the Judo Club needs one more member to participate. So, Medaka volunteers her and Zenkichi, who have both been practicing Judo for years, to help train the club and borrow Zenkichi for the match.