Sensei Shizuka Shinsetsu (Voiced by Hynden Walch) is a young and beautiful scientist and martial arts master. She was born and raised in Tokyo, Japan. She was the one who created Butterfly, the fifth member of the Powerpuff Girls. Her first name is Japanese for tranquil, while her last name is Japanese for kind. She is both of these.
When making Butterfly, she used all the usual ingredients, except she added ramen to the mix. When she was born, she raised her as her own. After a few weeks, she started to teach her the ways of Karate and chi. She also helped her discover her other hidden potentials. Thanks to Sensei Shinsetsu, Butterfly became wise beyond her years. Her arch nemesis is Fanghai. When the Powerpuff Girls asked her if Butterfly could join them, she insistently agreed, knowing that she would learn much on her journeys, and aid her teammates greatly.
Sensei Shinsetsu has the appearance of an anime character. She has long black hair, oriental skin, and pink eyes. She wears a green sleeveless shirt, orange shorts, a black belt, and grey Kung Fu shoes.