Tsuyoshi Yamaguchi

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.

Shima (Riki Takeuchi), the right-hand man of his yakuza boss and renowned hitman, suffers from kidney disease. Interned in the hospital, he meets Junko, a nurse. When Shima is shot, she goes home and heals him. Gradually a relationship is formed between them and Junko gets pregnant. But Shima cannot escape the obligations of his clan and the disgust of Junko...