Constantine Asimov, a Russian GRU Spetsnaz operative, emerged as the sole survivor of his unit after the final battle against the Disas King at Mt. Aso. During this conflict, he interacted with Yoshiaki Iizuka, discussing the weakened state of global militaries and humanity's heavy reliance on magical girls for survival.

Assigned as the handler for Tamara Volkova (Phoenix Tamara), Asimov initially remained unaware that Russian military authorities were brainwashing her using a fantasy-granting device. When he uncovered this truth, his trust in Russian command eroded. He covertly became an informant for Japan's M Squad, operating under the codename "Friend." His actions were driven by a determination to save Tamara from exploitation and to safeguard his own family, revealing a protective nature contrasting his hardened soldier exterior.

Prioritizing his family's well-being and refusing to participate in unethical operations like Tamara's brainwashing defined Asimov's moral stance. This commitment ultimately led him to betray Russian interests, actively aligning himself with M Squad's objectives.