It was Jongkey, set during Dream Girl era, Jjong was having an identity crisis o e  his suddenly emerging feelings for Key. The biggest clue( + note) I have is that Jjong had this dream where Key was so.e half Fox person and he had red hair.  Also during the recording Jjong was having trouble portraying emotion for the dream girl so he just pictured his ideal type, which turned into Key. That's all I got guy I'm sorry. Thanks to any help.