Also known as: 西川葉子
A former Ojou-sama from Sansha San'You with long Purple Hair and Purple Eyes. She is usually depicted in her School Uniform - a Serafuku with a cream coloured top and pleated Brown Skirt.
Most of her diet consists of bread crusts.
Youko is good friends with Odagiri Futaba and Hayama Teru and is often followed around by her former butler Yamaji Mitsugu.