World renowned doctor of engineering Caff who'd always been ridiculed for his small stature disappears one day. He kidnaps Young-hee's father Dr. Yoon who is a physicist. But Hoon, who still hasn't gotten over his failure to save Miran, refuses to get in the control seat of Robot Taekwon V again. However, they rescue Suelle who was chased by Caff's spaceship. But she is actually spy for Caff and she begins to siphon information about Robot Taekwon V's features and technical information. Suelle falls for Hoon but when she is found out by Young-hee, she runs away to Caff. Dr. Yoon researches energy 90 as part of Caff's plans to take over the universe. Meanwhile, Caff uses former martial arts champions who lost to Hoon to build a nemesis to Robot Taekwon V. Their power begins to overwhelm Robot Taekwon V. But with the help of Suelle, Dr. Yoon transfers Energy 90 to Taekwon V and Taekwon V and Hoon are able to defeat the enemy robots. Caff surrenders and kills himself. His base explodes and Suelle is killed also. Hoon and Young-hee rescue Dr. Yoon and return to earth.