When the girl Natsu woke up, there was only the sea around her. She was caught in the suddenly roaring sea and came to the island with Arashi, Chanmaru and Mudan. The island was covered with uncultivated jungles, giant plants, and ferocious animals and insects attacked one after another, and they were involved in a life of survival accompanied by death. At this time, they heard an incredible plan from the mouth of a person who called himself a guide. It was the 7SEEDS plan, which was a plan to freeze young and healthy humans to prevent the extinction of mankind and leave the seeds of mankind in the world after the disaster. They were stunned when they learned for the first time that they were the humans chosen by this plan. The young people chosen by the 7SEEDS plan still desperately survived in this drastically changing world even if they were exposed to the cruel environment.