Meeting Jooin purely by chance, Cain calls out to Jooin by shouting "master". Looking at Jooin's bewildered face, he then proceeds to explain that Jooin was Cain's master in the past life and Cain is very happy to meet him again like this. His Korean is not very fluent. Even as Jooin dismisses his claims as strange, they exchange email addresses. Cain keeps messaging Jooin in his broken Korean. At first, Jooin doesn't reply but soon he starts finding Cain adorable. Jooin gets a chance to go on a trip to Cain's country with his classmates. Cain greets him at the airport with a bright smile. On his trip, Cain gets to spend a day with Jooin and both start getting closer. Soon Cain visits Korea to learn Korean, but his main reason meeting Jooin. Even though he comes from a supposedly rich family, Cain lies to Jooin about not having a home and moves in with him. As the two start to live together, they grow closer. Cain cooks for Jooin and takes care of him. He doesn't like how Yahwi treats his "master" Jooin, but doesn't say anything as Jooin said it shouldn't concern him nor to get involved. Gradually, Cain developing feelings for Jooin. Over time, it is revealed that Cain might actually have been an animal (maybe a dog or a wolf) under "Jooin's" care, in the past life.