Eunseo and Myeongjin are two childhood friends who grew apart as they got older, but things take an unexpected turn when Eunseo gets a packet of jelly beans from a mysterious old lady. The next morning, Eunseo becomes the size of a little bean himself! However, the only person Eunseo can ask for help is Myeongjin. Life is suddenly so different for Eunseo; Will they be able to find out why he shrunk, and bring Eunseo back to his normal size? And what will this do to their friendship?