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.
Watunuki assists Domeki's professor in ascertaining the nature of a charm and is later reunited with Yuko in a dream and therefore free to leave the wish-granting shop.