That Time I Got Reincarnated As A Slime

The story follows Satoru Mikami, a salaryman who is murdered and then reincarnated in a sword and sorcery world as a titular slime, who goes on to gather allies to build his own nation of monsters. It was serialized online from 2013 to 2016 on the user-generated novel publishing website Shōsetsuka ni Narō.