Junichiro Iwaki was originally an alien from the "Human Planet" who traveled to Earth and became a famous gymnastics coach. However, Junichiro resigned from his position to train children in martial arts after sensing that a being known as King Flasher and his army would attempt to invade Earth. Junichiro's predictions turned out to be true, and the children in turn were able to transform Junichiro into Human No. 1 by using a device known as a "Human-Sign", to help fend off the invaders. With the help of his brother Junjiro, and his friends Rumiko Hoshiyama and Yasubee Hirai, Junichiro managed to destroy King Flasher. This did not stop the Flashers however, as a new leader was appointed named Grand Flasher, who immediately battled and killed Junichiro. Junjiro then stepped forward to battle Grand Flasher, and was transformed into Human No. 2 by the Human-Signs. During their battle, Junichiro was miraculously transported to the Miracle Zone dimension, which revived him and fully healed his wounds. Returning to the front lines, the Humans were able to drive Grand Flasher away. From that point on, Junichiro and Junjiro fought off the hordes of kaiju deployed by the Flasher Corps, until they were able to confront Grand Flasher and destroy the invaders once and for all.
Credit to NTV Do not Report/False Report
