Literally "brown hair", chapatsu is the once rebellious, once trendy style of bleaching (and occasionally dyeing) hair, found among Japanese teens.

While the style itself began to show up in Tokyo streets mid- to early-1990s, the word did not appear in Kojien (one of Japan's authoritative dictionaries) until 1998. The style first gained popularity among adolescent girls, seeking to accentuate their tanned skin (rebelling against more traditional definitions of beauty), but quickly grew into the mainstream.

See also Ganguro.