Go! Go! Loser Ranger!, also known as Ranger Reject, is a Japanese manga series written and illustrated by Negi Haruba. It has been serialized in Kodansha's Weekly Shōnen Magazine since February 2021, with its chapters collected in twenty-two tankōbon volumes as of May 2026. An anime television series adaptation produced by Yostar Pictures aired from April to June 2024. A second season aired from April to June 2025.