This may well be my favorite manga, and I have read a LOT of manga. The best thing about this manga is the characters, and the plot primarily serves as a way to learn about the characters. The main cast is made up of middle school students who have been tasked with piloting a giant mech called "Zearth", and after each one pilots the mech, they die. The pilot is chosen at random from those contracted to pilot it, but they are told in advance. The story is structured around each pilot's last days on earth before they fight to save it. None of the characters are ignored, and all of them get some nice development through the story.

Altogether, I think that the characters in this story are all written well, and resemble real people quite closely. Through the main cast, we see the world through many lenses, as they live very different lives, and we get commentary on society and on varying types of people within it. It is interesting.

One thing about this manga that is particularly stand-out is how the author handles death, in that the characters react in very real and visceral ways.