The world is full of many monsters and the world is separated in two. Werewolves, vampires, swans, and mythical creatures all live together on the Other Side while ordinary people live on the Life Side. Life during these times was difficult as there was a lot of wars between both sides. Two lovers, one Other prince and one Life princess, loved each other but their parents try to drive them apart. As a result their relationship is pushed to the limits and they choose to end their lives. They make a promise to come back and look for each other no matter what. In 2021, both worlds have finally come together and live at peace. Jake, a vampire descendant, is part of a Kpop Idol group named Enhypen. Kang Seo-Jun is a waitress who hopes to one day fulfill her dream of becoming a singer. Both live their lives as best they can but feel like something is missing. One day, Jake runs into Seo-Jun as she is running to her job when they both feel a shock course through their body and memories of different lives hits them, leading them to see each other more and more often. With the memories comes an Evil that both have to defeat. What will happen to these two? Will they find the missing piece they are looking for?