Еномото Ю

The focus of Chapter 3. Kei's older sister, Yuu is a cheery girl who never hesitates to make friends. Although she appears to be a little ditsy, she carries an avid interest for just about everything, making her very knowledgeable on a variety of subjects. As a result, she, like her sister, garners a lot of attention from many guys. However, whether its being oblivious or just nonchalant, she doesn't seem to mind being friendly with all of them.