Janken (じゃんけん, Janken), sometimes Janken-Pon (じゃんけんぽん, Janken-Pon), is “Rock, Paper, Scissors” in the English-speaking world, and it is the most popular of a subset of games played using only one’s hands, known as “Ken games” (ken asobi/拳遊び, “Ken games”). It was invented in the late 19th century and acquired popularity world-wide throughout the 20th century.
Downtown (ダウンタウン, Downtown) is a Japanese comedy duo (kombi) consisting of Hitoshi Matsumoto (松本人志, Hitoshi Matsumoto) and Masatoshi Hamada (浜田雅功, Masatoshi Hamada). Downtown is probably the most influential kombi to come from Yoshimoto Kōgyō, and is arguably the most popular kombi in Japan today.
As with many owarai kombi, there exists a boke and a tsukkomi. Matsumoto is the boke of the two and often puts up with light physical abuse (it is common for the tsukkomi to slap the boke on top of his head whenever he says something rude or ridiculous) from Hamada, the tsukkomi. Hamada is also known to attack other tarento and celebrities (such as Ayumi Hamasaki) when they give boke-like responses to Downtown’s questions. Hamada’s aggressive ways have earned him the nickname of Do ESU no Hamada (ドＳの浜田, Do ESU no Hamada), or “Hamada the Super Sadist.”