The Ex-Queen of The Nekomi Institute of Technology until Belldandy turned up and diverted everyone's attention away from her, although not intentionally. Sayoko is a rich kid who is used to winning, which makes her position very desperate at the moment as she doesn't seem to be winning in the popularity battle between Belldandy and herself. The arrival of Urd didn't help either.
A little on the unscrupulous side, she will not hesitate to resort to dirty tricks to get what she wants. She is however, with a conscience. In chapter 44 (The Queen of Vengeance), Sayoko had a chance to destroy Belldandy's gift to Keiichi, but decides against it after spending a day with him. It is also revealed later on that she might actually be falling for Keiichi instead of just treating him as a trophy.
