Eriol came to Japan in order to aid Sakura and force her to use her own magical powers to convert the Clow Cards into Sakura cards. This is necessary as the cards take their magical energy from their master, but until Sakura converted them, they could not use her magic and were slowly dying. The guardian Yue also was suffering the same fate, forcing Sakura's brother to "feed" him all of his magical power to prevent Yue, and his false form Yukito, from dying.
Sakura does not become aware that Eriol is causing all of the magical disasters that are causing her to convert the cards until near the end of the series when Eriol reveals himself to her. He puts the city to sleep and challenges Sakura to convert the last two cards, the Dark and the Light, which must be converted together. After Sakura successfully does so, he then tells her that she is now more powerful than Clow Reed and asks her to perform one final task for him: to divide his own magical power between himself and her father Fujitaka—the other reincarnation of Clow Reed—so that Eriol will no longer be the most powerful magician in the world. He then takes Sakura, Syaoran, Tomoyo, Yue, and Cerberus to his home where he explains why he had to give her a reason to convert the cards, as her doing so without a need could have sent the cards out of control or drained Sakura's own life.
Eriol's true age is unknown, as he used his magic to halt his aging process to remain the same physical age as Sakura. He is romantically involved with Kaho Mizuki, whom he originally sent from England to aid Sakura in the Final Judgment and who offers Sakura support through letters during the second arc. At the end of the manga series, she returns with him to England, and in the second anime movie, they are shown together when Sakura calls for advice.
In the anime series, Eriol is the sole reincarnation of Clow Reed, with all of the elements from the manga regarding Fujitaka's relation to Clow and inheriting of half of his powers removed. The final explanation at Eriol's house is also shifted slightly so it takes place the day after the final battle, rather than immediately after, and it is done because Sakura seeks him out rather than his giving an invitation.
The character of Eriol is voiced by Sasaki Nozomu. In the Cardcaptors English adaptation, his name is changed to Eli Moon and he is voiced by Bill Switzer. In the English dub of the second film, his voice is supplied by Johnny Yong Bosch.
In the anime adaptation, he voiced by Katsuyuki Konishi in his true form, and by Yumi Touma in his false form. In the second Cardcaptor Sakura movie, his false form briefly appears and is voiced by Philece Sampler. In the English adaptation Cardcaptors, his name is changed to Spinner Sun and both forms are voiced by Colin Murdock.
In the anime adaptation, she is voiced by Ryoka Yuzuki. In the English adaptation, Cardcaptors, both her true form and false form is called Ruby Moon and she is voiced by Willow Johnson.
Sakura's older brother. He enjoys teasing Sakura, calling her the 'Monster' for fun. To Sakura, he's just the regular annoying big brother. In reality, he really does care for her and wishes to protect her. He and Syaoran don't get along. He has countless part-time jobs, ranging from a waiter at an amusement park to a Teddy Bear Mascot, and shows up virtually everywhere Sakura goes.
Little is initially said about Fujitaka's family or past. During the second half of the series, it is revealed that when Clow Reed divided his soul, seeking to no longer be the most powerful magician in the world, he split it into two halves, one which became Eriol Hiiragizawa holding all of the magic and memories, and the other being Fujitaka, who has no magic of his own, but fathered the one who would inherit the cards. It is stated that Fujitaka has no magical powers of his own, but he is also unaffected by other people's magic, such as the Eriol's sleep spell. At the end of the series, Eriol gives half of his magic to Fujitaka. This enables Fujitaka to finally see the spirit of Nadeshiko, who has been watching over her family since her death.
In the anime adaptation, Fujitaka's role as the other half of Clow Reed's reincarnation is completely removed as is his immunity to Eriol's magic and he is never able to see Nadeshiko's spirit. He is voiced by Hideyuki Tanaka. In the Cardcaptors English adaptation, his name is changed to Aiden Avalon and he is voiced by Brian Drummond.
In coming to Tokyo, Meiling intends to help Syaoran gather the Clow Cards, and actively dislikes Sakura. As the series progresses, Meiling develops a grudging respect for Sakura that turns into a good friendship by the time Meiling returns to Hong Kong in episode 43. During her initial visit, Meiling seemed to recognize that Syaoran was falling in love with Sakura, but it wasn't until she briefly returned in episode 60 that she fully acknowledges and accepts Sakura as the person Syaoran loves. Wanting to keep his promise, Syaoran attempts to tell her that he loves Sakura, but Meiling interrupts and tells him that she knows because he is now calling Sakura by her first name, something he only does for his sisters and herself. She smiles at Syaoran with tears in her eyes and declares that the engagement is called off, then quickly leaves. Meiling spends the night at Tomoyo Daidōji's house to release all of her sadness through much screaming and tears without burdening Syaoran. At the end of the episode, Meiling returns home and is not seen again in the main series. She returns in the second movie, with Syaoran, and together with Tomoyo tries to help Sakura confess her own feelings to him.
Unlike Syaoran, Meiling has no magical abilities, relying solely on her physical fighting abilities and a healthy dose of pride. Her lack of powers, however, results in her hindering more than helping Syaoran in most battles against the cards. She challenges the The Fight card in episode 20, and was nearly badly wounded and had to be rescued by Syaoran. Recognizing that she was being a burden, Meiling grew upset and lashed out at Syaoran. However, she was then able to be an aid to him while fighting The Twin card, as their years of practicing martial arts together enables them to match the card's synchronized fighting style.
The character of Meiling is voiced by Yukana Nogami. In the English adaptation Cardcaptors her name is changed to Meilin Rae and her relationship with Syaoran is changed from cousins to childhood friends. She is voiced by Nicole Oliver. In the English dub of the second movie, she is voiced by Julie Maddalena.
In the anime adaptation, Chiharu and Yamazaki's relationship is less clearly stated, but she gives him chocolates for Valentine's Day and they are frequently seen together both in and out of school. When Sakura is shown a world where everyone connected to the cards has lost their feelings for the one they love the most, Chiharu and Yamazaki are shown reacting to one another as virtual strangers. Chiharu's name is changed to Chelsea in the Cardcaptors English adaptation of the series, and she and Yamazaki are changed from a couple to cousins displaying sibling rivalry.
She is voiced by Miwa Matsumoto in the original anime series, by Jocelyne Loewen in Cardcaptors and by Dorothy Elias-Fahn in the English dub of the second film.
In the original Japanese series, Maki is voiced by Kotono Mitsuishi. In the English dub Cardcaptors, her name is changed to Maggie.
After meeting Sakura for the first time, Sonomi realizes that Nadeshiko had lived a happy life and is able to come to terms with the marriage. At times, she still treats Fujitaka as a "rival" competing to love Sakura more, but she also helps him pass on gifts from Sakura to her grandfather and to arrange for Sakura to meet her great-grandfather while on a family vacation. Sonomi shows great affection for Sakura, wanting to join her and Tomoyo whenever Sakura comes over to visit.
In the Cardcaptors English adaptation, her name is changed to Samantha Taylor and her declaration of love for Nadeshiko is modified to a purely familiar love rather than a romantic love.
Sonomi is voiced by Miki Itō.
In the anime adaptation, their relationship is not shown in the same light. Their engagement and more romantic scenes between them are removed, and Rika notes that Terada reminds her of her absentee father. Terada is also shown accepting cakes made by Rika and in accepting the bear and naming it after his "hardest working student." In the Cardcaptors English dub, he is simply called Mr. Terada, and all aspects of the romantic relationship between Terada and Rika are completely removed, with Rika's shyness and reactions to him made to appear to be more of a general fear of men than romantic feelings.
In the anime series, he is voiced by Tōru Furusawa for the first season and first movie, and by Katsuyuki Konishi for the second and third seasons and the second film. In theCardcaptors dub, he is voiced by Brian Drummond.
During the series, Rika is shown to be in a romantic relationship with her teacher Yoshiyuki Terada. In the manga series, they are engaged to be married when she is old enough, and they frequently spend time alone together on "dates." In the anime adaptation, the engagement is removed as are many of their dates, however they are still shown to have affection for one another. Rika gives Terada the hand-made teddy bear she made, and he names it after her. In both the manga and anime, when Sakura uses the Illusion card to stop Rika's attacks, she calls the image "Sensei" which means "teacher" in Japanese. During the final judgement when Yue show's Sakura a world where everyone has lost their feelings for the one they love the most, Rika is shown handing Terada a paper without her usual blush and shy look.
In the Cardcaptors English adaptation, Rika's name is changed to Rita and all hints of her relationship with Terada are removed. Instead of being a good student, she is depicted as having trouble with her school work and her blushing around Terada is explained away as being embarrassed at having to stay after school so often.
In the original anime series, she is voiced by Tomoko Kawakami. In the English dub of the second film, she is voiced by Stevie Bloch.
During an interview, Clamp noted that they had originally intended for the character to have a long-distance boyfriend, but the chapter featuring that story was cut out of the series.
Naoko is voiced by Emi Motoi. In the English adaptation Cardcaptors, her name is changed to Nikki and she is voiced by Kelly Sheridan. In the English dub of the second movie, she is voiced by Sherry Lynn.
Though Nadeshiko has died, her love for Fujitaka and her children, and visa versa continues to live on. She frequently visits the family as a winged spirit, though initially only Toya can see her. In the manga, it is noted that Toya likely inherited this power from Nadeshiko, implying she too could see spirits. Throughout the series, she worries over Sakura as the young girl begins gathering the Clow Cards. When the Illusion card tricks Sakura into walking off a cliff, Nadeshiko's spirit grabs her arm and keeps her from falling until Yukito Tsukishiro arrives to catch her. Later in the series, when Sakura develops a high fever, Nadeshiko appears and puts her hand on Sakura's forehead, lowering the fever. When Fujitaka goes to talk to her father for the first time in a long time, she rains Sakura blossoms over them to show her happiness that they are reconciling.
The family is shown to also still love her, most noticeably through a picture kept in the dining area near the kitchen table. Fujitaka changes the picture each morning and Sakura always greets the picture while coming to breakfast. At the end of the series, after Fujitaka receives half of Eriol's powers, he and Nadeshiko are happily "reunited" as the magic allows him to finally see her.
In the anime adaptation, Nadeshiko's role is generally unchanged, except that Fujitaka is never able to see her as he does not receive any magical powers. She is voiced by Yūko Minaguchi. In the Cardcaptors English dub, her name is changed to Natasha Avalon.
Fellow classmate Chiharu Mihara often interrupts his stories so others know when he is lying, and proceeds to punish him for lying by pretending to strangle him or by dragging him away by his collar. While the two often seem to be arguing, they are actually a couple and have known one another since kindergarten. She is the only girl in the series that he addresses by her first name. Despite Yamazaki's often joking nature, he is shown to have a serious and sensitive side as well, willing to jump into a fierce wave to attempt to save fellow classmate Rika from drowning, and leaving Chiharu alone to talk to Sakura when Sakura was struggling with her feelings for Syaoran.
In the anime adaptation, Yamazaki is the only character to be rarely shown with his eyes open. His relationship with Chiharu is left more ambiguous, though on the day of Judgement when Sakura is shown a world in which everyone losing their feelings for the person they love the most, Yamazaki and Chiharu lose their feelings for each other and are shown to be strangers.
In the Cardcaptors English adaptation, Yamazaki's name is changed to Zachary Marker and all hints of his relationship with Chiharu are removed. Instead, they are said to be cousins and the Chiharu's joking strangling of Yamazaki is considered to be sibling rivalry.
Yamazaki is voiced by Issei Miyazaki in the anime adaptation, and by Philip Pacaud in Cardcaptors. In the English dub of the second film, he is voiced by Joshua Seth.