OVA
Description
Jiro is an android built by Dr. Komyoji to fight the terrorist group DARK and safeguard the scientist's children, Mitsuko and Masaru. His unique design includes an incomplete "Conscience Circuit" (GEMINI), granting him sentience and emotional growth but leaving him susceptible to external control, like Professor Gill's hypnotic flute. Exposure causes intense pain or temporary loss of autonomy, though he sometimes overcomes it through willpower or counter-sounds.

His default appearance is human, handsome with black hair, brown eyes, and denim attire. He transforms into his combat form, Kikaider, using the phrases "Switch On!" or "Change, Kikaider!". The Kikaider form features a distinct half-blue, half-red color scheme, representing the duality of his incomplete conscience circuit—blue for "good," red for potential corruption. This form possesses superhuman strength exceeding 1,500,000 horsepower, durability against extreme conditions like 5000-degree flames, and combat techniques including the "Denji End" electromagnetic karate chop, "Double Chop," and "Giant Swing Throw." He also has self-repair functions and uses a signature red guitar as a leitmotif and a motorcycle called the Side Machine.

Jiro's personality evolves significantly. Initially activated with childlike naïveté and confusion about his identity, he grapples with existential questions. Despite insecurity, he exhibits deep compassion, protecting humans and showing empathy even towards antagonistic siblings. He forms a strong emotional bond with Mitsuko, developing romantic feelings she reciprocates, though their relationship is complicated by his fear of endangering her. His core drive is a desire for humanity, a "Become a Real Boy" archetype. This idealism is tempered by moments of rage when allies are threatened or confronting Gill, revealing a capacity for vengeful violence, such as nearly killing Gill after Dr. Komyoji's apparent death or destroying Destructoids indiscriminately in berserk states.

His interactions with other androids define key conflicts. As Dr. Komyoji's creation, Jiro is the "older brother" to later models like Ichiro (Kikaider 01) and Rei (Kikaider 00). Ichiro lacks a conscience circuit, resulting in a pragmatic, emotionless demeanor contrasting with Jiro's empathy, while Rei is more primitive. Jiro's most persistent adversary is Saburo/Hakaider, a cyborg initially housing Dr. Komyoji's brain and later implanted with Professor Gill's brain. Hakaider serves as Jiro's dark counterpart, embodying ruthless efficiency without moral restraint. Their intensely personal battles culminate in Hakaider's destruction during SHADOW's uprising, where Gill (in Hakaider's body) manipulates Jiro into a final confrontation.

Jiro's arc culminates in the Kikaider 01 OVAs. After DARK's defeat, he encounters its successor, SHADOW, led by Gill-Hakaider. SHADOW targets Akira (Gill's son) to power the Armageddon Lord superweapon; Jiro protects Akira alongside allies like Rieko. Gill implants a "submission chip" in Jiro to enslave him. Instead, the chip suppresses his GEMINI circuit, amplifying latent aggression and prompting him to destroy Hakaider, Ichiro, and Rei. This fratricide, committed under partial control, devastates Jiro but paradoxically fulfills his desire for humanity—he interprets the resulting guilt and moral conflict as proof of a human soul. Ultimately, he accepts his dual nature as both machine and human, choosing solitude to atone while acknowledging his conscience will remain in "eternal conflict."

A later OVA special, *The Boy with the Guitar: Kikaider vs. Inazuman*, explores Jiro's continued struggle with the submission chip's lingering effects. Fearing he might harm Mitsuko and Masaru, he isolates himself until Hanpei Hattori finds him. During a battle with Inazuman, triggered by a psychic adversary's manipulation, Jiro breaks free from the chip's influence. This reaffirms his self-acceptance, concluding with him expressing hope for eventual reconciliation with his family.