A kid infected with an unstoppable bioweapon runs with a girl he barely knows while his own body becomes a weapon he can't fully control. The OVA burns through seventy minutes like it's being hunted, every scene another mutation, another impossibility, another reason Ikuroo should already be dead. Araki's proto-JoJo energy is all over this: body horror that doesn't exist to disgust you, it exists because the protagonist's survival IS the transformation happening in real-time. The animation catches a very specific moment in late-80s OVA culture where ambition and budget collided and nobody cared about explaining the science. Watch it once at full volume and it's done with you before you can ask what you just saw.
A shadowy weapons program has created the perfect bioweapon: BAOH, a parasitic organism that transforms its host into an adaptive killing machine. When their test subject, a young man named Ikuroo, breaks free from captivity with a mysterious girl named Sumire in tow, the organization that made him becomes desperate to recapture or eliminate him before BAOH reaches full maturation. The parasite grants Ikuroo extraordinary abilities, reshaping his body on the fly to counter any threat. But control is slipping away. As Ikuroo and Sumire flee across the countryside, BAOH awakens deeper inside him with each passing moment, hungry and increasingly difficult to suppress. The line between Ikuroo's humanity and the monster he's becoming grows thinner. Sumire's strange precognitive visions might be the only way to stay ahead of their pursuers, but even she doesn't know what Ikuroo will become if BAOH fully takes hold. What unfolds is a brutal sprint where survival means embracing the very weapon everyone fears.