CLAMP is the name of an all-female studio of Japanese writers and artists. At the time of publication the 4 members of CLAMP were Ageha Ohkawa, Mokona, Satsuki Igarashi and Tsubaki Nekoi.
After aiding twin sisters in their troubles with words, Watanuki befriends the spirit of a dead boy and prevents a child from falling victim to malevolent spirits.