Mars Red is set in Tokyo in 1923, where a black-market blood product known as Ascra begins to drive a surge in vampire activity. As the illegal trade spreads through the capital, the military responds by forming Code Zero, a covert anti-vampire unit made up of vampires and placed under Colonel Yoshinobu Maeda, with Lieutenant General Sounosuke Nakajima supervising the operation.
Working from the shadows, Code Zero is tasked with tracing the source of Ascra and containing a crisis that threatens to spill across a city already divided by secrecy and fear. Its members have to depend on one another while navigating unstable powers, divided loyalties, and the uneasy distance between their former human lives and the identities they now carry. Mars Red combines military action, gothic horror, and political intrigue, but its real tension comes from the investigation itself: every clue deepens the pressure in the capital, and every step forward makes the line between duty, survival, and allegiance feel more fragile.
