Chinpui movie.

In an unplanned field trip, Riko is transported to an alternate Japan where metal-based life forms known as Mimesis ravage the world. Only girls equipped with LBX armored weaponry can stand up to this scourge. Joined by four other displaced young women, Riko will have to adapt to save humanity. The hope of a planet now rests on these heavy metal soldiers who desire one wish—to return home again!

Teenage boy Lin Fei was unable to practice martial arts due to a defect in his meridians. After witnessing his master and his best friend die in the battle in the Black Abyss, he began to practice an ancient art of artifact refinement. He vowed to avenge them and hunt down the leader of the Black Abyss, even if it cost him his own life. A mysterious power revived him in a new era, and Lin Fei was determined to rebuild his sect and make it flourish.