A brave man with tremendous courage and enthusiasm, and the strength to never give up for the sake of life—even at the possible cost of his own.

Former astronaut and test pilot for the Space Development Corporation. In 2003, he had been in orbit testing an experimental space shuttle when an extraterrestrial object (later classified as EI-01) suddenly appeared in his flight path, smashing his shuttle out of the way. This left the shuttle disabled and Guy himself in a near-death state.

The alien mechanical lion, Galeon, would then appear and deal a crushing blow to EI-01, sending it out of orbit to land on Earth. Thereafter, Galeon would find the critically wounded Guy and return him to the Space Development Corporation. Adapting Galeon's technologies, his father Leo Shishioh would create a cyborg body for his son (with a G-Stone-powered mechanical heart), saving his life and giving him superhuman strength.

Cyborg Guy

Though legally declared dead, Guy would join the Gutsy Geoid Guard and become the commander of its Mobile Unit. Serving alongside his old high school sweetheart Mikoto Utsugi, he would boldly stand against signs of the coming alien threat. This would bear fruit when the Zonder Robo EI-02 emerged from Garbage Island in 2005. GGG's grand counterattack prepared, he would perform Fusion with Galeon and Final Fusion with the GaoMachines to become the Super Mechanoid GaoGaiGar and destroy EI-02, beginning a long-running battle against the Zonder threat.

While operating in the field, Cyborg Guy was equipped with "Ultimate Armor", derived from the ID Armor previously worn by the disbanded secret organization ID5. When in battle, he entered Equip mode, readying himself and placing a data-gathering lens over his right eye (the data being displayed with the shout of "Library"). On his left hand, he wore a GaoBrace that served to protect the G-Stone that provided him energy, as well as incorporating a signaling mechanism that utilized that power for calling Galeon with the "projection beam". The rear of the GaoBrace contained a sheath for Guy's Will Knife, a G-Stone-based bladed weapon with variable sharpness (determined through the will of the user; hence the name).

In emergency situations, Guy could tap into the energy batteries (the orange canisters linked in series that fall on either side of Guy's face) to enter a golden-colored Hyper Mode—raising his fighting power to its absolute limit, though the effect could only last three minutes.

Cyborg Guy had the additional ability to operate in the vacuum of space for limited periods of time.

In this form, Guy often called himself "mankind's strongest Cyborg" (jinrui saikyō no Cyborg). Despite the bold claim, Guy's cyborg body is still somewhat less than invincible. In fact, until Mamoru's restorative powers came to light, it would take time for Guy to recover from battles, and successive uses of Hell and Heaven would send him to the emergency room.

(Source: Wikipedia)