taken from ANN
Two years after the end of the original Soukyuu no Fafner TV series, Kazuki is slowly losing hope that Soushi will return to Tatsumiya Island as he promised. Meanwhile, the awakening of Misao Kurusu, the new core of the island, sets in motion a series of events that will decide the very fate of humanity AND the mysterious Festum aliens who are moving to renew their attack on earth.

when i watch fafner i feel like it is the combination of evangelion + gundam seed