Kowa Period Year 7, there lived the brothers Roze and Ash, the "Nameless Mercenaries (ナナシの傭兵)" brothers of the old Hokkaido block of the United States of Japan now occupied by the "Neo Britannian Empire". Known to be undefeated in their operations with Ash's advanced Knightmare piloting skills and athleticism and Roze being the brains with his intelligence gathering and strategizing, until they have to deal with the impregnable "Situmpe Barrier (シトゥンペバリア)" energy wall for the next 4 years. But a new threat arises for the world when Neo Britannia's 100th emperor, Chalice al Britannia, and his Knights of Einberg begin their move after being repelled by Black Knights' Liberation Plan. To counter that threat, Roze and Ash accepts the request to assist the Japanese resistance group, the "Seven Shining Stars (七煌星団)" to take on Neo Britannia and recapture Sakuya Sumeragi.