KinKi Kids is a Japanese popular group under Johnny & Associates. The group members are Koichi Domoto and Tsuyoshi Domoto.

They made their debut in 1997 with their single Garasu no Shounen (Glass Boy), which made them a number one on the hit chart ORICON for many weeks. They are also listed in the Guinness Book of Records, where they are credited with having most number of consecutive singles that debuted at number 1 on their charts. These singles include Anniversary, Natsu Moyou, Harmony of December, and the most recent Secret Code. As of writing, all of their singles have debuted at number 1.

Widely known in Japan, the KinKi Kids are very popular among girls of all ages, and their subscription concerts even draw boys. Not only do they sing, but they are also talented actors, having appeared in popular dramas and sitcoms. For example, Tsuyoshi played a part in Kindaichi Shounen no Jikenbo (Young Kindaichi's case files) and Summer Snow, and Koichi was in Remote. They have their own variety show called Domoto Kyoudai (The Domoto brothers). However despite their shared surnames, they are in fact completely unrelated and hail from two different prefectures in the Kinki region.

To commemorate their 10th anniversary on 21 July 2007, KinKi Kids released a 10th Anniversary Best-Hit Album titled 39 on 18 July 2007. The numbers 39 are read as "san-kyuu" in Japanese, which sounds like "thank you" in English, signifying KinKi Kids' thanks to their fans for their support these last 10 years. The album features the top 11 song favourites, as voted by fans as well as 2 individual 14 song favourites lists from Koichi and Tsuyoshi, coming to a total of 39 songs, hence the title.