"Once on This Island" is a musical that tells the story of a young girl named Ti Moune who lives on a Caribbean island divided by class and wealth. The narrative unfolds as she falls in love with a wealthy boy named Daniel, who comes from the other side of the island. The story is framed by a group of storytellers who guide the audience through Ti Moune's journey of love, sacrifice, and the power of belief. The musical explores themes of fate, love, and the influence of the gods who watch over the characters' lives.