Masami Shimoda

When the sky turns red, the moon turns black, and monsters begin roaming the streets, Satsuki Kakeru is at a loss for what to do. Along with his best friend Yuka, they try to decipher why they have been sent to this strange world, which is seemingly empty aside from themselves. However, when the "Red Night" ends, Kakeru and Yuka believe it was all a dream—until it happens again, and they are left in a dangerous situation. They meet four others in the same predicament: Kusakabe Misuzu, an expert swordswoman; Tachibana Kukuri, a strange mute girl who looks uncannily like Kakeru's deceased sister; Hirohara Yukiko, a lively young girl whose personality reverts to that of a cold killer when her glasses are removed; and Tajima Takahisa, a young pyrokineticist. As the six of them band together to survive and discover what this mysterious world is, things take a turn for the worse as six shadows appear before them... [Written by MAL Rewrite]

In the distant future, since the Earth has become overpopulated, efforts to find and colonize on other planets have begun. However, one of the ships, the "Mesopotamia" malfunctions and all but 6 of its inhabitants are all killed. the remaining 6 manage to escape to a nearby planet named "Terra ll ", which is similar to Earth in many respects. However, all of them are male. Therefore, as to not let their efforts go to waste, they begin to set up 6 countries and to reproduce through cloning and genetic engineering. however, there are still no women, and to make up for it they create lifelike advanced female androids called "Marionettes" which do everyday chores and work. However, they are all emotionless machines. But one day, a ordinary boy named Otaru finds and awakens 3 special battle type Marionettes that have emotions due to a "Maiden Circuit" within them. It's up to him then to teach them and allow their emotions to grow, and when a nearby country threatens with world domination, it's up to to Otaru and his "human" Marionettes to protect their country.

The lives and loves of a gang of high school friends, tracked over the school year of 1999.