At 17 years old, Kenji was the youngest member of the Gorengers. He was training at the Kansai branch of EAGLE's Japan Block when the Black Cross Army attacked.

As a youth without a care in the world, he could sometimes be brash and temperamental, though his agility and sharp senses were unmatched. As Midorenger, he was armed with the razor-sharp Midomerang, which could be flung at enemies or used as a handheld weapon to cut and slash through opponents.

His Midomerang was later upgraded to the New Midomerang, which was larger and more powerful. He also carried the Mido Puncher, a high-tech slingshot weapon used to fire pachinko-ball pellets and, on occasion, specialized explosives. Kenji operated the super motorcycle Green Machine and its successor, the Green Star.