Yuuko Aioi is one of the five main characters of Nichijou, alongside her friends Mai Minakami and Mio Naganohara, Nano Shinonome and Hakase. She is an energetic high school student with short brown hair. Usually her friends call Yuuko by her nickname, Yukko (ゆっこ). Throughout the series, negative things sometimes happen to Yuuko, even if they logically shouldn't, such as when she and her friends were playing a crane game and the claw was somehow broken off.
