The Tsubasa: Reservoir Chronicle manga series and its respective animated adaptations feature a large cast of fictional characters designed by Clamp. The series takes place in a fictional multiverse with parallel dimensions where several characters – taken from many of Clamp's past works – can appear in several of the universes as having the same character names and designs but differing histories and settings. The story begins in the desert Kingdom of Clow where Syaoran, a devoted and kind archeologist, investigates its ruins. His childhood friend Sakura, the kind and well-loved princess of the kingdom who holds an undeveloped magic, mysteriously has her memories scattered across the dimensions in the form of feathers and will die if they are not returned to her. To save her, Syaoran takes her to the Dimensional Witch Yūko Ichihara where he meets two more of the series' protagonists who have arrived with similar wishes: Kurogane, a rough-mannered ninja, and Fai D. Flowright, a laid-back magician with a dark past. In order to journey across the dimensions, they receive a cheerful creature named Mokona Modoki, the fifth of the group, from Yūko. On their journey across the dimensions, the group decide to join Syaoran to retrieve Sakura's feathers, as a mean to accomplish their wishes. The protagonists are all linked by the series' main antagonist, the sorcerer Fei-Wang Reed who oversees the journey. Using Osamu Tezuka's Star System, Clamp designed the series' characters based on the ones they used in their previous works. Few of the characters appearing in Tsubasa: Reservoir Chronicle are the exact ones from other series, most notably the ones from xxxHolic, series which often crossovers Tsubasa. The characters from Tsubasa: Reservoir Chronicle have received positive critical response by critics due to their traits, and development across the series. Various types of merchandising have also been released based on them. Creation and conception Using the ideas of Osamu Tezuka and his Star System, the series contains various crossover characters from many of Clamp's series, including most notably Cardcaptor Sakura, RG Veda, X and xxxHolic from which the main characters are derived. The series' characters were designed by Clamp writer Mokona, while Syaoran and Sakura were chosen as its protagonists because Clamp wanted to use ones whose original series had happy ending. However, in contrast to Syaoran Li and Sakura Kinomoto from Cardcaptor Sakura, Clamp pointed out that they would have to go