There are 4 "circles" that take place in this episode, the most of any episode in the series.
This is the first episode that has a scene that actually takes place outside. All other scenes take place on a set.
When the sensei is setting a self-defense scenario for Jackie, Donna has her arms crossed on her chest. This is extremely rude in Japanese culture, and in a martial arts school, it is seen as an outright challenge to the instructor.