学者たちによって、「近い将来、巨大天体が降り地球は様々な災害に見舞われ、恐竜が滅亡した時と同じような状態になるであろう」と予測されたことから、人類の滅亡も危ぶまれるこの事態に、各国首脳らが極秘会議を重ねた結果、「7SEED'」と呼ばれるプロジェクトが誕生した。
それは、若く健康な人間を選んで冷凍保存し、地球が災厄に襲われている間眠らせ続け、やがて人が住める状態になったとコンピューターが判断した時に自動解凍を行い放出するというものである。人類の種を災厄が過ぎ去った後の世界にも残そうという壮大な計画であった。
Natsu wakes up to find herself thrown out in the middle of an ocean. The last thing she remembers is going to sleep in her own bed. She finds she's with 7 strangers, and none of them remembers boarding a plane or a ship. The group gets stranded on an island full of strange plants and creatures. There, the "guide" explains to them about 7SEEDS, a government project to ensure humanity's survival, set into motion when scientists around the world predicted the destruction of earth. In Japan, 5 groups of 7 people, plus a guide for each group were put into cold sleep, only to be released when the climate is suitable for their survival. But when Natsu's group is confronted with the proof that they are indeed in Japan after some kind of catastrophe, each have to deal with the fact that life as they know it is over. No help is coming. They have to survive on their own on this land, where the environment has seemingly turned back to Jurassic times.
