Bioman must rescue two boys who possess an ancient treasure map that leads to Biobase, making them targeted by Gear.
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.
The Ganglar have stolen the Lupin Collection, treasures left behind by the famous phantom thief, Arsène Lupin. Phantom thieves are fighting to take back what was lost. Police are fighting to protect the peace.
