welcome to the world of the missing manga, it's IMPOSSIBLE to get this one I barely managed to grab the first volume and half of the second from mirc but i really don't remember where any more, a group used to translate it but they stopped doing it, really too bad because i've seen volume 19 in japanese and the guyver is fuckin kickass, upgrades everything, so you might only find some chinese or japanese versions but looking for them on the net takes ages and it isn't worth it, the guyver anime series can be found on any p2p program like Edokey the crappy OVA too the series is better it's also available on DVD my friend has it it's his all time favorite so sorry you won't find the guyver manga in english, if you do though definately let me know i've been wanting to read this manga for such a long time now, so your best bet is p2p programs and look for the 12 eps and the OVA isn't that bad but crappy if you've seen the 12 episodes and i suggest you check dailymanga.org maybe they still have the name website and irc channel for the group that did the first two volumes of the manga