KISS KISS / Lucky Guy is Kim Hyun-joong's first Japanese single. It mostly consists of Japanese versions of previously released Korean songs from his mini albums Break Down and Lucky. The only original Japanese song is "Hohoemi No Chikara" (Japanese: ほほえみのちから), which is featured on one of the three available editions.[1][2][3]
Kim Hyun-joong promoted "Kiss Kiss" (Japanese Ver.) on TV programs and released music videos for the aforementioned song and "Lucky Guy" (Japanese Ver.).