xxxHOLiC (TV)

Ep. 16, time 00:20:47. Watanuki just got out of a well. Yuuko says: "You are just like Sadako!" This is a reference to Sadako from the movie "Ring".

The "xxx" in the title does NOT indicate anything pornographic, but instead, indicates variability, and is not pronounced. Thus, the title is to be pronounced "Holic."

At the beginning of chapter 6 (Indulgence), the drug store Watanuki is visiting is attended by Kazahaya and Rikuou, characters from Gohou Drug/Legal Drug, another CLAMP's story.

In episode 1, Yuuko said "In order for you to gain something of value,the price can be anything of equal value.".This quote is from Fullmetal Alchemist.

In episode 3, Moro and Maru are heard reading a book that Chii from the CLAMP series Chobits also enjoyed. In this same episode, Chii's ears are used as walkie-talkies.

In episode 7, Watanuki gets compared to Nobita. Nobita is a main character of the anime Doraemon who often cries to Doraemon to get his help.

In episode 8 when Watanuki is cleaning out the storage room you see Maru and Moro beating the dust out of a butterfly rug. Maru is holding the red bat Yuuko bought in episode 6. Moro is holding the staff Fay D. Flourite (Tsubasa Chronicles) gave as compensation for a wish.

In episode 9, Yoshiki (the man Ran meets with immediately following her visit with Yuuko) is wearing a Led Zeppelin "Zoso" logo shirt and necklace.

There are a couple of references to Yamamura Sadako (山村貞子), the main character of the Japanese 'The Ring' series of movies. Sadako is famous for her scene in which she crawls out of a television playing the cursed tape. Scenes of such a character crawling in a Sadako-like fashion can be found in episode 12 [Natsukage/Summer Shadow] and episode 16 [Saikai/Reunion].

In Episode 15, Watanuki goes to help the trouble sister with her forehead. In the same room, there is a poster of him and Yuuko on the wall for the xxxHOLiC anime

In episode 16, when Watanuki is looking at the hairpins in the shop, the brand/maker is the same as the name of the company that Tomoyo Daidouji is president of in the beginning of the second season of the Tsubasa Chronicle anime.