The Guyver: Bio-Booster Armor

Shou and his friend, Tetsurou, stumble upon a strange orb-like mechanism, the Guyver Unit, in the woods. It physically bonds with Shou and turns him into the alien soldier, Guyver. His mission is to protect the Guyver Unit from the Japanese corporation known as Chronos. They are after it and two other units just like it. To retrieve the object, they send out vicious monsters known as Zoanoids. So no one is safe in Shou's life; not even himself.

The plot of this OVA is a rough adaptation of the first four chapters of the Guyver manga. It covers the same basic elements of these chapters; Genesis of the guyver, Fight with Vamore, Fight with Guyver 2 and the introduction of Guyver 3. Main differences are the exclusion of Tetsuro and his replacement by Mizuki, The replacement of Lisker with a female Agent "Valcuria", and thus a female Guyver 2. There is also a look at Sho's psychology of how he deals with his situation including a very harsh moment where his friends are assassinated in cold blood. One night, high school student Sho Fukamachi discovers a mysterious metal object. Then in a blinding flash of light, Sho finds that he has accidentally fused with the Guyver, a mecha of mysterious alien design. Now, to save his girlfriend, Mizuki Segawa, along with the entire world, Sho must become the Guyver to fight the Chronos Corporation and their biocreatures, called Zoanoids, who are hell-bent on world domination.

Lurking under the facade of everyday life lies a dark world of pain and destruction.​ The world is controlled by a sinister brotherhood that hides their fangs behind masks of humanity.​ They are the Chronos Corporation.​ While investigating a mysterious explosion near his school,​ Sho Fukamachi happens upon the Chronos Corporation's greatest weapon: a techno organic suit of bio armor known as "the Guyver.​" But Chronos is determined to conceal their secrets at any cost.​ Sho soon finds himself relentlessly pursued by its army of horrific bio-monsters.​ With nowhere to run,​ Sho is forced to call upon the fearsome power of the Guyver and rip his opponents limb from limb in a desperate struggle for survival.​

In the middle of an all-out invasion by extra-dimensional aliens, rebel alien scientist Zeku gathers teenagers with various psychic powers, like Isamu. Once on board Zeku’s ship… and on board with his mission to defend the human race from extinction… Isamu and his fellow teens use mental energy to create enormous suits of armor with which to battle the Garadain Empire. Through the course of the series, the teammates fight each other, fall in love, and battle wherever necessary to protect Earth, whether that’s at home, in deep space, or even while trapped on the alien world itself.