Top 6 in Top 15 most popular mecha comics about walking machines today.
An Otaku who loves Mecha is reincarnated into another world as Ernesti Echevalier (Eru). There exist huge humanoid machines called "Dark Knights". Dreaming of becoming the operator of those Robots, Eru and his two childhood friends: Archid and Adeltrud Olter aim to become the Operational Knights, pilots of the "Dark Knight" machines.