That time I got reincarnated as a slime

Rimaru takes on the mask of his long-lost friend Shizu, and in an effort to bridge the gap between the land of the monster and the land of humans, Rimaru take his Shizu mask and take care of the orphans Shizu managed. But his Shizu mask is that of a young lady and Rimaru manages to make enemies before he has a chance to help the children.