Final answer:
Centorea refers to Kimihito as 'Master' in the Monster Musume series, underscoring her chivalrous and honorable nature in the context of her centaur traditions.
Step-by-step explanation:
In the Monster Musume series, Centorea addresses Kimihito as 'Master'. She is a centaur character who views Kimihito as her master in a knightly manner, following the tradition of her people who seek a human master to serve. Centorea's formal and respectful way of addressing Kimihito highlights her honorable personality and her dedication to the code of chivalry that is significant in the series.