Takuma Ichimonji is the son of Dantetsu Ichimonji, the astronaut accused of betraying and destroying Earth's first mission to the resource-rich planet Promete. Orphaned and stigmatized as the traitor's son after the incident, Takuma was raised by Dr. Oedo at the Tobishima Island research base. At age 16, driven by a desire to restore his family's honor and clear his father's name, he joined the Jasdam project as a cadet pilot, having endured years of social neglect and abuse due to his father's alleged crime.

Physically, Takuma sports thick, spiky sideburns reminiscent of 1970s anime styles. He wears a distinctive red-and-white pilot suit and a red helmet. As the main pilot of the Danguard Ace's Guard Launcher component, he controls the robot's upper body and head from its cockpit. His training under the enigmatic Captain Dan—later revealed to be his brainwashed father, Dantetsu Ichimonji, concealed behind an unremovable memory-suppressing mask—was strenuous and severe, yet Takuma respected Captain Dan's unparalleled piloting skill. This rigorous preparation proved vital, enabling Takuma to effectively operate the Danguard Ace during critical missions, including single-handedly piloting the Satellizer component when Captain Dan was incapacitated during an attack.

Takuma's character arc centers on reconciling his father's legacy. Initially believing his father died in disgrace, he discovers Dantetsu was framed by the antagonist Mr. Doppler (also called Chancellor Doppler or General Toppler) and actually escaped Doppler's mind control. Takuma's journey evolves from seeking redemption for his father's alleged betrayal to directly combating Doppler's forces alongside him. The dynamic between Takuma and Captain Dan adds emotional depth, fueled by their shared commitment to overthrowing Doppler's tyranny over Promete.