4 years since the final battle between Celestial Being and the UN Forces. Humanity, having established the Earth Sphere Federation, forms an independent security preservation force, Arrows, separate from the formal Federation army to further unify nations and the will of mankind. But the reality was the inhumane oppression of anti-government powers, doctrines & ideologies in the name of unity. Saji Crossroad, who followed the path to becoming a space engineer to keep a promise to Louise Halevy and fulfill a dream, is also compelled to become involved in Federation government reform. Meanwhile, Setsuna F. Seiei, surviving the final battle 4 years ago, saw the future of the world that had been changed by Celestial Being. With the defeat of guardian Alejandro Corner, he dreamed of a peaceful world without conflict. But before his own eyes was the reality of the continuing strain on peace, the oppression caused by Arrows. He decides once more to fight with Gundam, the power with the potential to change the world. Where will Setsuna's and Saji's paths take them as the world is set into motion once more?