Ikuko Itoh is a Japanese animator and character designer, mostly known from the work on Princess Tutu and Sailor Moon. I believe it's good to know work of animators from different countries and styles.
Her animations are always very expressive, well - timed and beautiful. Same goes to characters. It is very easy to see, when comparing different seasons of Sailor Moon, as there was many different animators working. Episodes that she mostly worked on have characters very expressive and fluid, with amazing little details and emotions.