Chryiss
In fact, I forgot to update that the base illustration I originally used was merged into a montage with another fantasy-like one (that V-shaped white strip). As for the impression thing, of course you're right, but I'm fine as long as someone who knows some Japanese culture or history has the first impression I expect in that regard.
Now, about the story of my novel, it has its basis in certain videogames such as Ghost Recon or Splinter cell (they are part of the Tom Clancy franchise, whose books also served as inspiration for my story), and even the Deus Ex Franchise (mostly its atmosphere). But, in general terms, you can think of a Neon Genesis Evangelion-like plot, with teenagers with their own personal dilemmas working for a military organization that wants to protect the world. The action, however, revolves around them employing Iron Man-like suits with modern military engagement tactics plus martial arts (the armors are more flexible, of course).
My greatest source of inspiration, however, is the Power Rangers TV show. Just compare the recent Dark Knight movies made by Nolan with the 60s’ Batman TV show, both having the same basic premise. One is more mature, dark, and relatively serious, while the other is childish and comical.