What is "ko's"

Usage examples of "ko's".

However, Juliet decided she would combine both roles, spending half the year with Angeline Fowl, and the other half honing her martial arts skills in Madame Ko's camp.

That carpet merchant might have been in Madame Ko's employ, or he might have been an innocent civilian, who happened to stick his nose in where it didn't belong.

Her hyperactive disposition had caused her to fail more than one class at Madame Ko's Academy.