From the introduction: Welcome jumper, to a strange new world. Known as Planet Bomber (Or Eris if you prefer a more believable planet and less silly name), it is a peaceful world inhabited by humans, beastfolk, and the strange and curious androids known as the bombermen, manufactured by the brilliant Prof. Ein with the help of Dr. Mitsumori. Among the most exalted of the bombermen is white bomber, known to some as Shiro. 10 years in this world wouldn't be so bad, right? With stalwart protectors like the bombermen and relative peace in present times surely there can be no danger right? Unfortunately wrong I'm afraid, my friend. In 7 years a floating fortress will descend upon this world and commence its attack.