The earth is about to be destroyed, Nymph and Astraea are dying one after another... In order to save the world, the only remaining Ikaros takes Sakurai Tomoki to the sky city - Synapse. In the beautiful sky, Ikaros recalls the past days... The time spent with his master, every day, every minute, every second, is very happy... What is the final fate of the burning Ikaros and Sakurai Tomoki...?