Bioman must rescue two boys who possess an ancient treasure map that leads to Biobase, making them targeted by Gear.
| Actor | Role |
|---|---|
 Ryōsuke SakamotoShirō Gō / Red One | Shirō Gō / Red One |
 Naoto ÔtaShingo Takasugi / Green Two | Shingo Takasugi / Green Two |
 Akito OsugaRyūta Nanbara / Blue Three | Ryūta Nanbara / Blue Three |
 Sumiko TanakaJun Yabuki / Yellow Four | Jun Yabuki / Yellow Four |
| MMichiko MakinoHikaru Katsuragi / Pink Five | Hikaru Katsuragi / Pink Five |
| MMunemaru KôdaDoctor Man | Doctor Man |
 Yûko AsukaFarrah | Farrah |
 Hirohisa NakataMason | Mason |
| SStrong KongoMonster | Monster |
 Yukari ÔshimaFarrah Cat | Farrah Cat |
 Yoshiko OhtaPeebo (voice) | Peebo (voice) |
| SShun YashiroMesserjuu (voice) | Messerjuu (voice) |
 Keisuke YamashitaPsygorn (Voice) | Psygorn (Voice) |
 Masahiro AnzaiZyuoh (Voice) | Zyuoh (Voice) |
| HHiroshi IzawaMettzler (Voice) | Mettzler (Voice) |
| KKankou NagaiAquaiger (Voice) | Aquaiger (Voice) |
| NNorikimi OotsuKeita Nakayama | Keita Nakayama |
| SShinjiro KatagiriHisao | Hisao |
| NNahoko NomotoCat 1 | Cat 1 |
| SShinobu ShimuraCat 2 | Cat 2 |
| KKaori KikuchiCat 3 | Cat 3 |