Following his breakup with Jackie, Marco moves to Mewni full time. Given a second chance to be with Star, will he finally find the courage to recognize and act on his feelings? Meanwhile, a sinister plot to upend the Butterfly Dynasty is brewing as new enemies rise. Can Star discover the threat in time to save her family?

Marco Diaz is a normal 16 year old boy who got accepted into a transfer program for a new school; although, he may have bitten off more than he can chew. Turns out that this school is in another dimension. At least he keeps making friends with a group a of cute monster girls who help him adjust to his new life. Monster Girl AU, will eventually have older Mariposa, will have FemTom

His whole life Marco Diaz has been raised by monsters, living under the cruel rule of their leader, Toffee. But one day Marco escapes into Mewni where he meets a magical princess and Mewman like himself, who begins teaching him all about her world. Together they will learn about life, love, and the lights within each of them, as they change their world forever.