Rei ni hajimari rei ni owaru: it begins with courtesy and ends with courtesy. The phrase is used for judo and kendo. A judo article says that the etiquette of judo is fixed, and that its rules of etiquette go back to bushidō.
The All Japan Kendo Federation’s guidebook for junior high school kendo teams uses a longer form: Rei ni hajimari, rei o motte okonai, rei ni owaru. It begins with courtesy, is carried out with courtesy and ends with courtesy.