Yuuki Juudai (遊城十代 Yūki Jūdai?) is ChikyuuRed (チキュウレッド Chikyūreddo?) the Red Ranger of the Chikyuurangers and the leader of the team. Juudai was originally a student from the Duel Academy placed in Slifer Red due to his poor grades in the entrance exam, but graduated right after the end of his four years. He is shown to be headstrong, optimistic, and fun-loving, but that doesn't stop him from being a good leader. His Chikyuu Power is Fire, and gains the ability of super strength.