Salaryman ga Isekai ni Ittara Shitennou ni Natta Hanashi

This is a wonderful and amazing story of an office worker boy he is a hard-working servant and he was born again in a fantastic world. He is surprised when he finds out that he has become one of the 4 heavenly kings and gained a high-rank scale in the service of the Demon Lord. He is trying to solve issues with magic and modern technology which challenges him. This anime series is full of action, comedy, and cleverness. He maintains a balance between responsibility for the demon lord and his own ability of ideas, these characters make this series interesting and exciting.