Mahou? Sonna Koto yori Kinniku da!

Summary

There was a youth who lived deep inside a forest, his name was Yuri. After many years of training, he gained a special trait which made his body able to withstand almost every kind of magic. One day, a beautiful elf named Firia, who was lost had arrived at his house. Yuri, who wanted to see the outside world, together with Firia, set out on a journey around the world. (Source: Novel Updates, edited)