Keiko Kurakake is a scientist in the Shibasato research institute. One day she gets a call from Professor Yamazashi, who tried to perform human cloning the year before. She accepts his invitation and goes to meet him; on arrival she is shocked to see that the professor is now a young man: the secret to his new youth is due to the Cambrian factor.Professor Yamazashi aims to recreate the unprecedented leap in evolution called the Cambrian explosion with modern humanity, hoping to rule the world as their creator!"