I'm not a veteran of war stories, but my interest in this novel was piqued when a Hollywood movie adaptation was announced (branded Edge of Tomorrow in many territories). I have not yet seen the movie (it has only just barely come out in Japan), but I will probably give it a view at some point so that I could compose a compare/contrast post.
For now I will focus solely about the publication itself. The afternoon of a enormous struggle arrives... and Keiji is quickly murdered. It's a jolting start that strikes off the center plot part of the story: the protagonist is caught in a time loop. Day after day, he is drawn into the battlefront, only to be painfully murdered again and again. His only hope is to become a soldier strong enough to endure the battle, and so he enlists the help of his commander and an American soldier named Rita Vrataski.
It is a rough and gritty story, and also the author did well to get across precisely how miserable an experience it is out from the battlefield. The process in which Keiji comes to grips with the heinous circumstances he's gotten himself caught up in is explained with gloomy straightforwardness, but the writer does well to combine in some comedy (dark and otherwise) to shake up things a little. Keiji makes for a strong narrator, along with the narrative is paced in such a manner in which the central plot element of repeating exactly the same day forever not actually feels repetitive. Keiji is constantly trying something new, and the author is ready to jump ahead several time cycles in a time to keep things going at a lively pace.
True Martial World is a quick read, and a page-turner that's effective primarily because of its engaging premise. It's a narrative that's held up nearly entirely by its own sci-fi concept though, therefore if the assumption does not interest you there might not be much else for the publication to offer. That said, I found it gratifying from begin to finish, and I look forward to the possible sequel.