The daughter of Duke Green, Esmeralda is Mia's best friend. In the previous timeline, she had promised to host a tea party with Mia to help with the stress she was under due to the ongoing famine and revolution. When Mia went to the party, she found the Greenmoon estate deserted and came to realize that the Greenmoons had fled Tearmoon to avoiding being killed along with the royal family and believes Esmeralda's promise was just a lie. It is later revealed that Esmeralda had intended to keep the promise, but was forced to flee due to her father, being dragged out of bed and taken to another country to remain safe. She greatly regrets not being able to keep her promise with Mia, especially after learning of her execution. In the current timeline, her relationship with Mia has greatly improved, with Mia properly accepting her as her best friend. This comes after helping to save Mia when they are stranded on a deserted island, and plays a major role in discovering the conspiracy surrounding the founding of the Tearmoon Empire. Esmeralda has also come to properly express herself, most notably by referring to her servants by their names instead of their position, such as her maid Nina.