CLAMP is an all-female Japanese manga group that's been around since the mid-1980s, though they've gone through some serious lineup changes over the years. The crew started as an eleven-member dōjinshi circle before narrowing down to seven by their official debut with RG Veda in 1989. By 1993, they'd settled into their current four-person roster: leader Nanase Ohkawa (who briefly went by Ageha Ohkawa around 2006 before switching back), plus artists Mokona, Tsubaki Nekoi, and Satsuki Igarashi. What makes their setup unique is that the three artists rotate roles depending on the series.
They started creating original work in 1987 and have since become a juggernaut—nearly 100 million tankōbon copies sold worldwide by October 2007. Fans often note the group's ability to bounce between wildly different genres and storytelling styles, which probably has something to do with their flexible creative structure.
Content compiled by AnimeList.moe from publicly available sources.