Amari Mono Isekaijin no Jiyuu Seikatsu: Yuusha ja Nai no de Katte ni Yarasete Moraimasu

Shinichi Sagara, or Shin, works in a corporate sweatshop when he's swept up in an off-world transport meant to bring heroes. Transported to the Kingdom of Tondemo, where they exploit these off-world heroes' abilities, Shin's quick to sense something amiss and flees to another kingdom to begin a happy idle life in a mountain village. One day, Shin meets a nobleman that's locked up in a remote part of a lord's mansion. Will this completely change that quiet life in the countryside?!

Source: Alpha Manga