Read manga: Isekai De Uwamae Hanete Ikiteiku ~Saisei Mahotsukai No Yuru Fuwa Jinzai Haken Seikatsu~

manga
Summary:

A company drone who died from overworking was reincarnated as Sawadi, the third son of a merchant in a different world.His specialty is restoration magic and support magic. He used his cheat skills to come up with a new model of business. He decided to use his restoration magic to cure cheap slaves and make them earn money.Although his earnings are steadily increasing, he also has to suffer its consequence of his work load also getting increased... Will Sawadi ever be able to live leisurely without working?  The beginning of this lazy and relaxing fantasy, is starting here!---(JP) (https://ncode.syosetu.com/n1832fm/)  (https://gaugau.futabanet.jp/list/work/5de5ee3b77656147c9030000/novels)