Wooyoung and Taeyeon were childhood friends for as long as they could remember. When they were seven years old, Wooyoung promised Taeyeon that he would marry her when they grew up. However, he had failed to keep his promise to Taeyeon due to his complacency and his inability to express himself. On the day that Taeyeon is getting married, Wooyoung regrets not telling her his true feelings, so much that the fairy present in the church at that time took pity on him and gave him the chance to change his fate and fulfill the promise he made to Taeyeon. Will he be able to get her back, or will he lose her again, forever?