The RasenDragon is Koji's trademark technique. After trying for three weeks to master Rasengan, Koji was given one more challenge to prove he had true ninjutsu skill: to add his unstable fire element to the technique. The stubborn shinobi had made many efforts to create a Fire Rasengan, failing every time. He felt that it was impossible to merge an unstable element to a technique which required absolute control. Still, constant urges from Minako Uzumaki, his sensei, had driven him to continue his training to create the technique. During the attempts to create Fire Rasengan, Koji had created many botched and odd jutsus, including Fire Style: Blazing Pillar Jutsu.