According to the official website, minori (the game production company of "ef" series) announced a new PC game "eden* -They were only two, on the planet-" to be released in 2009. The detail of the game will be given in Monthly Comptique magazine to be released on Nov 10th.
Human beings faced the danger of extinction in 100 years. To survive and escape from the earth, Project "Pherix" was carried out. By the genetic engineering, humans became immortal and ready to leave the planet. 99 years had passed and Shion, the core of Project Pherix, finished her task. She chose to remain on the earth. Haruna Ryo was ordered to stay with her to protect her. On the vanishing planet, a quiet life of the two started.