Mr. Children (ミスターチルドレン, Misutā Chirudoren^?), commonly called "Misuchiru" (ミスチル^?), is a Japanese rock band formed in 1988 by Kazutoshi Sakurai, Kenichi Tahara, Keisuke Nakagawa, and Hideya Suzuki. As a group, they are one of the most successful Japanese rock artists, having sold over 50 million records and creating the "Misuchiru Phenomenon" (ミスチル現象^?) in the mid 1990s in Japan. They held the record for the highest first week sales of a single in Japan for 15 years, with 1.2 million copies of their 10th single "Namonaki Uta" (名もなき詩^?), have 30 consecutive number 1 singles, replaced Glay as the all-male band (with 3 or more members) to have the most number 1 albums on the Oricon charts, and won the Japan Record Award in 1994 for "Innocent World" and in 2004 for "Sign". As of 2012, Mr. Children has published fourteen original studio albums and 34 physical singles, along with five compilations, a live album, and fifteen home video releases. The band's music is mainly composed and written by lead singer Sakurai, with the exception of the Suzuki-penned songs "Asia" and "#2601" from the albums Atomic Heart and Discovery, and occasional collaborative song writing with producer Takeshi Kobayashi.

Mister, usually written in its abbreviated form Mr or Mr. (American English), is a commonly used English honorific for men under the rank of knighthood. The title derived from master, as the equivalent female titles, Mrs., Miss, and Ms, all derived from the archaic mistress. The title master was retained and used for boys and young men, but is now less commonly used. The plural form is Misters, or the abbreviation Messrs (UK) or Messrs. (US) ( /ˈmɛsərz/). This is an English abbreviation of the French "messieurs" (French pronunciation: [mesjø]), sometimes pronounced /ˈmɛsərz/ in English.