Doraemon: Nobita and the New Steel Troops—Winged Angels (2011)
Nobita discovers a giant robotic hand in his backyard, which turns out to be part of a powerful robot named Zanda Cross. With Doraemon’s gadgets, he and Shizuka assemble the robot, unaware that it belongs to an alien army planning to invade Earth.
They soon meet Riruru, a humanoid girl from the Robot Army, who initially follows orders but gradually changes after witnessing Nobita’s kindness. As the Robot Army attacks, Nobita and his friends, along with Riruru, fight to protect Earth. In the final battle, Riruru sacrifices herself to stop the invasion, and the Robot Army is defeated.
In the end, time is reset, erasing the events, but Nobita feels a deep connection, hinting that their friendship will never be forgotten.