By the year 2120, humans have successfully colonized other planets following the near devestation of Earth from the last great world war. However, on Gloire, one such colony are surprised and unprepared at the arrival of The Zor, a group of beings whom were the original inhabitants of the planet and left following similar near fatal events. Coming to reclaim their former home world, a relentless war erupts between both races that ultimately leads to a cataclysmic showdown and into a no-win scenario for either. (Source: ANN)

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.

Private detective Hazama Itsuru is hired by Professor Tani to investigate a cyborg parts theft which eventually leads him to meet Sachiko Yokogawa, the original 8 Man's love interest. Living her new life working for the Biotecho Corp., Sachiko finds herself involved with a new 8 Man, who appears after Hazama is fatally wounded by an unknow cyborg. Amidst a violent urban background with cyber-junkies creating chaos around the city, this other 8 Man will fight criminals in a more agressive way.

After a slow but eventful summer vacation, Shuchiin Academy's second term is now starting in full force. As August transitions into September, Miyuki Shirogane's birthday looms ever closer, leaving Kaguya Shinomiya in a serious predicament as to how to celebrate it. Furthermore, the tenure of the school's 67th student council is coming to an end. Due to the council members being in different classes, the only time Kaguya and Miyuki have to be together will soon disappear, putting all of their cunning plans at risk. A long and difficult election that will decide the fate of the new student council awaits, as multiple challengers fight for the coveted title of president. [Written by MAL Rewrite]