Tank Knights Fortress

Tank Knights Fortress ( 무한 전기 포트 리스, Muhan Jeongi Poteuliseu, 無限戦記ポトリス) is a Korean-Japanese co-produced animated series by SBS Productions, Dong Woo Animation and Daewon Media of South Korea in partnership with SUNRISE, NAS and Bandai Visual of Japan.

Plot
Three Fortress Knights and a human boy named Yuma are about to shape the Fortress Planet, the home where robots live in peace. But the harmony was disrupted because of the sudden presence of a dictator Dark Fortress along with his evil schemes. Now it's up to the Fortriss Knights and Yuma, who accidentally got into the Fortriss Planet, to battle the evil forces maintain peace throughout the Fortress Planet.