Noein: Mou Hitori no Kimi e

A conflict erupts between two dimensions, one dedicated to protecting humanity and the other seeking to destroy all space-time. A unit called the Dragon Calvary travels across time and space in search of the Dragon's Torque, the only known means to halt the invasion. In the present, a young girl named Haruka and her friend Yuu consider fleeing their homes when they encounter a figure named Karasu. He identifies himself as a future version of Yuu and asserts that Haruka holds the key to stopping the threat.