The Kubernetes Upstream Training in Japan is organized by a team of active Kubernetes contributors, aiming to increase the number of contributors and foster community growth. The training program was launched in 2019 and is held one to two times a year, initially as a co-located event of KubeCon. Since 2020, the training has been conducted online. The program includes an introduction to the Kubernetes community, an overview of the Kubernetes codebase, tips for lowering participation barriers, setting up the development environment, and a hands-on session using kubernetes-sigs/contributor-playground.