Mitsuru Matsuoka performs his voice role as Kamen Rider 4 and also performs the series's theme song "time" under the special band Mitsuru Matsuoka EARNEST DRIVE.
Mitsuru Matsuoka melakukan peran suaranya sebagai Kamen Rider 4 dan juga melakukan lagu tema spin-off "time" di bawah grup musik khusus Mitsuru Matsuoka EARNEST DRIVE.