The year is 2050. Derrida Ivan (the protagonist) is a young engineer who has gained fame for his contribution to the development of the "Autonomous Machine DZ" at the manufacturing company Rebuild founded by his father. Once, Derrida and his colleague Nathan noticed a major flaw in the "DZ", but his boss did not listen to his advice at all. Annoyed, Derrida continued to delay responding even though he knew it was dangerous, and went to attend the birthday party of Nathan's beloved daughter Maggie. However, the next day after a moment of peace, Derrida and Nathan were attacked by a mysterious force. At the end of his escape, Derrida fell into a cryo-sleep device and opened his eyes again. Ten years had passed, and the world he looked at had long been desolate and fell into a state of war! Just as he was about to give up everything when he was attacked by the out-of-control "DZ" group, Derrida recalled Nathan's dying words. "Maggie is in your hands." Although he was confused about the fate that had befallen him, Derrida continued to move forward in order to find Maggie. Reunion transcends "time" - this is the story of a journey of longing.