Oshima Yuko (大島優子), nickname "Korisu" (コリス), born October 17, 1988 in Tochigi Prefecture, Japan, is a Japanese idol singer, actress, and model, as well as captain of idol group AKB48's Team K. She is also a member of the sub-unit Not yet. She has been a contributing member for all of AKB48's singles since "Aitakatta" in October 2006, except for "Chance no Junban", "Ue Kara Mariko", and "Eien Pressure".

Read more about 大島優子 on Last.fm.