Takashi, a Japanese citizen in isolation-era Tokyo, was transformed into a synthetic being by Daiwa Heavy Industries' experimental nanotechnology, administered as a disguised vaccine. This conversion brought significant side effects, including the gradual loss of free will and humanity as the nanomachines advanced towards the brain.

As a child member of the resistance movement led by Maria, Takashi actively participates in operations against Daiwa's control, demonstrating awareness of their activities. He is present when the captured infiltrator Vexille regains consciousness in the resistance hideout and informs her that Maria changed her clothes while she was unconscious.

Takashi's condition deteriorates as the nanotech progresses, extinguishing the residual human consciousness and emotions known as his "shards of humanity." This loss of identity transforms him into a fully robotic entity devoid of independent thought or emotion.

Confronted by Takashi's transformation and the imminent threat of him revealing the resistance's plans to Daiwa, Maria decides to kill him. This act prevents the compromise of their operations but highlights the irreversible consequences of the nanotechnology. Takashi's fate exemplifies the broader tragedy of Japanese citizens subjected to Daiwa's experiments, illustrating themes of identity loss and ethical conflicts arising from forced technological transformation.