In Japanese, wa yoわよ is a combination of two sentence-ending particles: wa わ, generally used by women, used to voice one's decision, surprise, conclusion, or opinion, and yo よ, used when correcting someone or informing, alerting them of something. In manga and anime, it's typically used by "rich girl," ojousama お嬢様 characters speaking in polite language: desu wa yo ですわよ, ~masu wa yo ますわよ, ~masen wa yo ませんわよ.
