Yuna is a young girl who enjoys crafting robot models. She lived alone with her grandmother until the elder passed away. Soon after, she is abducted and taken to a covert facility where she encounters an enormous mech. The piloted machines battle Ancient‑Jinki across the Grand Savanna, yet the real purpose of these clashes remains concealed. Yuna labors at the station in the facility for future so that one day she may pilot a mech and unveil those mysteries.