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.<br><br>
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.<br><br>
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.