It was supposed to be a joke, a temporary thing… Yami would be Prince Charming. Yuugi would play Cinderella. They changed the story a little, thinking it would be funny. It was a parody of sorts. That one kiss the two shared sparked several others and eventually started a long-lasting relationship. The Joker, as Yuugi affectionately dubbed him, took full responsibility in hooking the two up. He claimed that the two were so oblivious that he had to do something! One small joke sparked a loving relationship between Yami and Yuugi. Yes, the Joker was indeed a very good friend.