Doraemon: Nobita and the Steel Troops
When giant robot parts suddenly fall from the sky, Nobita and Doraemon secretly take them to the mirror world to assemble a massive machine they name "Zandacross." Realizing it might be a dangerous weapon, they keep its existence hidden. Soon after, a mysterious girl named Riruru appears, demanding Zandacross for an impending invasion-though she herself opposes the attack. As Doraemon and his friends team up to stop the invading robot army, they discover that Riruru may be the only one capable of ending the conflict.
