Kuromukuro

Yukina Shirahane visits her mother at the Kurobe Research Institute, where scientists study mysterious relics uncovered during the dam's construction. One of the artifacts releases someone who belongs to another age: the samurai Kennosuke Ouma.

When an unknown threat descends from the sky, Yukina finds herself beside him in the robot Kuromukuro. School life gives way to battles against invaders, while Kennosuke's memories hold clues connecting the past to the danger now facing Earth.