Houichi Kano, the Grandson of world famous inventor Hosuke Kano, is a student at Houwa High School in Musashino City. At the tenth anniversary of the first contact with the Riofaldians, the unveiling of an Elevator Ship designed for orbital transport between the Riofaldian home world and Earth is about to take place. However, this was just a ploy to take control of the Earth using their advanced technology and large Riofaldian work force on Earth to their advantage. It is now up to Houichi, with the help of Housuke, his school friend Akane and Isaka, to stop them and save Earth.
There is plenty of mecha mega-robot action, state of the art gunsuits, sexy shape-shifting androids and the reason why the manga is called Cannon God...
But the Riofaldian are one step ahead and they have a plan...
Houjin Exaxxion was partially published in English as Cannon God Exaxxion by Dark Horse, first in comic book format from November 21, 2001 to December 17, 2003, with a total of 20 issues (the first three volumes). Publication was included in the manga anthology magazine Super Manga Blast from issue 41 (March 31, 2004) to issue 59 (February 1, 2006), and finally, the title was published in standard tankoubon format, with five volumes released from December 4, 2002 to June 7, 2006.
Ultimately, I would say that this was a plot focused manga with a simple but solid plot. It was an interesting plot line in terms of action and suspense, though it didn't really have much depth to it beyond some superficial elements. Character relationships were pretty weak overall, and there were some issues with consistency, such as it felt like it never properly decided what role they wanted "grandpa" to play, but overall the plot and characters were simple enough that it was a pretty enjoyable plot to read through, even if it never really got you invested in anything. It brought up a lot of points, such as heroes during war, racism, propaganda,
the fault of government or civilians, etc. but didn't really properly say anything about them. Rather, it seemed more occupied with simply showing a story about fighting back against an alien invasion, and to that end while it was pretty simply, I thought it was a pretty decent story. The action, though also lacking the depth you would expect from mech action, was pretty solid, and the comedy was decent enough as well when it showed up at strange points. The art was pretty good too.
tl;dr: A story that occasionally tries to seem like its more than that, but is really just a simple but solid story about a guy fighting a war against aliens.