OVA
Description
Dr. Shikishima heads the weapons department at the Saotome Institute, recruited by Dr. Saotome based on his background developing arms for the Japanese military. His physical form bears severe disfigurement: a crooked jaw, partially bald scalp with graying hair, a damaged eye, visible battle scars, and metallic implants. Later iterations feature extensive cybernetic enhancements integrating weaponry and computer systems, typically clad in a white lab coat.

His personality embodies the mad scientist archetype, exhibiting an obsessive fascination with weapon creation and destructive power. He unhesitatingly examines corpses to study lethal mechanisms and expresses no fear of death. He actively desires an end caused by one of his own inventions, considering it a fitting conclusion. This mentality manifested when captured by an enemy using him as a hostage; unafraid of being killed by his own weapon, he made specific requests about how to be shot, unsettling his captors with his apparent madness. Among the Getter Team pilots, he shares the closest bond with Ryoma Nagare, frequently assigning him to test new weapons and retaining the handgun he gave Ryoma for future use.

Historically, he joined the Saotome Institute during the conflicts against the Dinosaur Empire and later the Hyakki Empire. He survived the Getter Ray meltdown that devastated the Institute, disappearing for decades afterward. During the Odo Island incident involving an early Godzilla attack, he witnessed the creature's rampage but failed to act when urged to use his plane’s weapons, resulting in severe casualties and lasting guilt. Years later, he resurfaced to rejoin Hayato Jin’s leadership at the Saotome Institute, now equipped with his weaponized cybernetic body.

His technical expertise covers designing infantry and mecha-scale armaments, including handguns capable of destroying tanks and semi-automatic rifles for Getter robots. He single-handedly reconstructed the original Getter Robo after its destruction, housing it in the Asama Getter Museum where he served as director, anticipating future threats. His later modifications allowed direct brain interface via control wires to command the Institute’s defense systems, such as the external missile arrays codenamed "Peacock Tail" and internal security – systems entirely of his creation.

In the alternate continuity of *Apocrypha Getter Robo Darkness*, he retains his core traits – deformed appearance, weapon-obsessed madness, and desire for a spectacular death – while serving the organization GETTER. Here, he explicitly calls the Getter Robo his "ultimate slaughter weapon" and exhibits lecherous behavior toward female characters.

His ultimate fate varies across media: in one narrative, a grenade detonated by Sho Kamui during a Saurian assault kills him in his laboratory, though his mechanized head is seen laughing mid-explosion, implying potential survival. In other continuities, his status remains unresolved following the final story arcs.