That Time I Got Reincarnated as a Slime: Trinity in Tempest

Tensei Shitara Slime datta Ken Ibun: Makuni Kurashi no Trinity

Against the odds, the little slime Rimiru has established his magical kingdom for all monsters, called Tempest, and it's thriving. But three visitors, Phos the fox girl, Stella the dragon girl, and Nemu the winged girl, come to pay Tempest a visit, they're stunned at just how quickly it's developed.

(Source: Kodansha USA, edited)