Maru-dashi and Moro-dashi
まる(Maru) and もろ(Moro) are very common syllables found in Japanese names. Watanuki Kimihiro had no reason to assume that their names were the buildup to a joke. But he is absolutely right - they aren't cute names! Both まるだし(marudashi) and もろだし (morodashi) mean "exposing yourself in public." It's almost as if Yūko had decided to call her two assistants "Streaking" and "Flashing."
In the manga by CLAMP, Yūko explains that the Kodansha Japanese Desk Dictionary, Second Edition reads hitsuzen (ヒツゼン) is "a naturally foreordained event. A State in which other outcomes are impossible. A result which can only be obtained by a single casuality, and other casualities would necessarily create different results."
Yūko: Mokona, since the part-time worker's come today, we're drinking! Drink 'til you drop, you know?
Mokona: We're gonna drink!
Watanuki: (points at Mokona) This black stuff bun is a drinking buddy? Moreover what's a Mokona?
Yūko: Oath. Promise. Contract. They must not be violated. These are things that cannot be betrayed. Specialties are also there. Unconcsious lies and warped truths. Warped truths, and the disclosure of evil intentions. The disclosure of evil intentions and unconscious lies. Who is this sinful one? Next ×××HOLiC: "Falsehood"
Shall I grant your wish?
Yūko: In this world there are many strange things. However, no matter how strange or bizarre a sight is, if there is no one there, if there is noone to see it, if people are not involved, it is just a simple phenomenon. Just something happens. That is because in this world people are the strangest beings.
Art Director - Hiroyo Izumi
Japanese Title: 「ヒツゼン」 - "Hitsuzen"
"Hitsuzen" literally means destiny, fate, or inevitability.
Clamp crossover: Cardcaptor Sakura
When Watanuki is in the warehouse, he passes the original staff that Sakura Kinomoto used in the Cardcaptor Sakura manga and TV series.
Mokona originally appeared in CLAMP's Magic Knight Rayearth. However, the Mokona in that series was white with a red jewel and only ever said, "Pū!" In the manga, ×××HOLiC's Mokona could communicate with the white Mokona in Tsubasa, who also received updates from the earlier Magic Knight Rayearth model. The black Mokona is simply Yūko's drinking buddy in the anime, but at least Mokona can still see spirits.