Yuuko Aioi is one of the main characters in the anime series Nichijou, which is known for its surreal comedy and slice-of-life storytelling. She is a high school student who is energetic, spontaneous, and often clumsy or unlucky, leading to many humorous situations. Yuuko is friends with Mio Naganohara and Mai Minakami, with whom she shares everyday adventures that are anything but ordinary. Despite her carefree and sometimes lazy demeanor, Yuuko has a good heart and values her friendships, making her a beloved character in the series.