OVA
Description
Baoh is both a parasitic organism and its human host, Ikuro Hashizawa. Artificially created by Dr. Kasuminome of the Dress Organization through brutal environmental adaptation experiments, the worm-like Baoh parasite resides within a host's brain arteries. Once implanted, it grants extraordinary abilities but inevitably kills the host upon reaching its imago stage after 110-112 days by laying eggs that hatch and rupture the body.

Ikuro Hashizawa, a 17-year-old, became the parasite's host after surviving a car accident that killed his parents. Captured during medical treatment by the Dress Organization, who murdered his parents, Ikuro was forcibly implanted with Baoh. Initially suffering amnesia, he gradually recalled fragments of his traumatic past while evading the organization.

The parasite triggers an "Armed Phenomenon" when Ikuro faces mortal danger or intense emotion, transforming him into a powerful, armored bio-weapon. Over time, Ikuro learns to partially activate Baoh's abilities without full transformation, indicating growing symbiosis. Key powers include superhuman strength, agility, durability capable of deflecting bullets, and wall-crawling; potent regeneration healing severe injuries and reattaching limbs, allowing survival even after brain destruction unless the parasite is incinerated (his blood can also heal non-hosts); indefinite suspended aging without oxygen or sustenance when submerged; a forehead tactile sensor detecting emotions and life forces, disruptible by specialized chemicals; and Armed Abilities like corrosive secretions (Meltedin Palm), retractable arm blades (Reskiniharden Saber), combustible hair needles (Shooting-Bees Stinger), and 60,000-volt electricity generation (Break Dark Thunder).

Ikuro's struggle focuses on retaining humanity while harnessing Baoh's powers. Early transformations are involuntary and primal, but his protective bond with Sumire, a psychic girl aiding his escape, anchors his humanity. This allows increasingly tactical use of abilities, like activating acid touch to save a girl from a train or deflecting sniper fire without fully transforming.

Confronting the Dress Organization to rescue Sumire, Ikuro defeats adversaries like the cyborg Dorudo and psychic Walken. Following a facility explosion, Baoh enters suspended animation underwater. Sumire senses he remains alive, awaiting reactivation years later. Weaknesses include vulnerability if the brain is destroyed before transformation and the parasite's inherent lifecycle limit, though Ikuro's merging with Baoh may override it.