One game I learned from the Kani Club improv workshop in Tokyo is Master and Servants. The idea of the game is simple: three players, one is the Master who is constantly demanding things of the servants. When the servants try to meet the Master's needs, the Master is never satisfied and yells at them. For example:
A volunteer describes an incident they experienced -- something embarrassing, funny, puzzling, etc. -- to the whole group. The joker asks questions to clarify details and verify understanding. Then, the joker asks for volunteers to enact the scene. They are free to improvise in any way they like.