Five descendants of the people showered with Bio Particles by Bio Robots five centuries in the past have become Biomen. They transform with the Bio Brace and fight using their Super Electronic Brains on their masks. Their Bioswords are equipped with sword and gun modes.

Ryōsuke Sakamotoas Shirou Gou / Red One
Naoto Ôtaas Shingo Takasugi / Green Two
Akito Osugaas Ryuuta Nanbara / Blue Three
Sumiko Tanakaas Jun Yabuki / Yellow Four II
Yuki Yajimaas Mika Koizumi / Yellow Four I
Yoshiko Ohtaas Peebo (voice)
Hirohisa Nakataas Mason
Hirohisa Soda
Takeshi Narumi
Yū Yamamoto
Tatsumi Yano