Not at all, in fact the mangaka was going to give it a GOOD END (well, relative to the story anyway) but turns out he was in NYC during 9/11 so that changed his outlook on the world enough to change the ending, so it got a BAD END.
Personally, I loved this manga and I thought the story was pretty good. I like that the reason why Japan is fighting a war with the rest of the world isn't clear to most of the characters (I mean, it would make sense it's because of Chise), that's realistic. People don't just live in a war zone and have complete knowledge of what's happening or why.
I also think Tetsu should have fucked Chise.