Kumasawa is a part-time worker who assists with domestic chores in Kinzo's mansion. She often shirks her responsibilites and likes to tell stories and jokes, especially outrageous ones involving mackerel. (from wikipedia)

Spoiler

She is actually the former Lady Beatrice, Virgilia (in episode 13). Virgilia is the one who taught Beatrice, her student, and she gave her name to her student.