ZhongTao

Zhongtao is the het ship between Zhongli and Hu Tao from the Genshin Impact fandom.

Canon
Canonically, both Hu Tao and Zhongli work at Wangsheng Funeral Parlor as its director and most revered consultant, respectively.

Hu Tao mentioned Zhongli in her character's teaser ("Hu Tao: Scared Yet?"), nicknaming him the "walking encyclopedia". Hu Tao also mentioned Zhongli in Part I Act I of her Story Quest (Papilio Charontis Chapter).

Zhongli mentioned Hu Tao in the third part of Archon Quest Chapter I Act III, referring to her as "Director Hu". Zhongli also wrote in a message on Wangshu Inn Bulletin Board that he should get back to Wangsheng Funeral Parlor after the rain stopped, otherwise Hu Tao may come there to drag Zhongli back herself.

In Hu Tao's Story 2, Zhongli is mentioned to be the person who Hu Tao trusts the most. Hu Tao and Zhongli also have voicelines about each other.

Hu Tao and Zhongli share similar color schemes - dark brown and black colored clothes which blend elements of traditional Chinese and modern Western costumes. Their physical bodies also share some resemblances, such as being among the few characters whose eyes possess exotic pupils, both wear red eyeliners and both of them also possess long hair with gradient color.

Both Hu Tao and Zhongli wield polearms, and the damage dealt by their attacks also scales with the total amount of their HP.

Gameplay-wise, the Hu Tao and Zhongli combo make a very good team composition:

Thanks to Hu Tao's HP burn mechanic as well as major damage boost when she's low in HP, Hu Tao could and should constantly be in a state of low HP to achieve peak performance. Because of that, most healers don't work well with Hu Tao as their healing can reduce her damage. Hence this is when characters with shield support come into play, and Zhongli is generally considered to be the best tank and shield bot in the game at the time this entry was first written.

Because of that, people also attribute intimacy to their respective roles in combat, with Zhongli as the solid enabler and defender of the reckless and suicidal Hu Tao.

Quote
"Zhongli looks young, but his personality is a bit dusty. Knows everything, but doesn't fret over anything. Hmm... Couldn't be that he's a...Hehe, forget it, whatever."

- Hu Tao's Voiceline about Zhongli

"The current overseer of the funeral parlor? Ahem. I cannot deal with that child."

- Zhongli's Voiceline about Hu Tao

"I should be getting back to the Wangsheng Funeral Parlor after the rain stops, otherwise Director Hu may come drag me back herself."

- Zhongli's message on the Wangshu Inn Bulletin Board

"I'm afraid I must leave now to handle things back at Wangsheng Funeral Parlor. I hope that Director Hu has been able to keep things under control for the moment."

- Zhongli's dialogue in third part of Archon Quest Chapter I Act III

"Though that walking encyclopedia Zhongli would no doubt have a completely different explanation..."

- Hu Tao's dialogue in Character Teaser - "Hu Tao: Scared Yet?"

"Oh, you know Zhongli? Well! That saves me a lot of explaining."

- Hu Tao's dialogue in first part of Hu Tao Story Quest Act I

"It would be best not underestimate someone as whimsical as her. However, should you enjoy surprises, then I believe a visit is in order."

- Zhongli's remark in Hu Tao's introduction on official twitter as well as forum

Fanon
This ship appeared shortly after Hu Tao's model was leaked, when very little was known about Hu Tao's relationships beside voicelines, dialogues and memos of various characters about her. Since Hu Tao is Zhongli's boss at Wangsheng Funeral Parlor, Zhongli was assumed to have a relationship with Hu Tao.

People generally find the dynamics of their relationship to be entertaining, or at least comedic. Considering that Zhongli (as Morax) is an extremely popular and respected deity gifted with exceptional strength and abilities whose contributions are unrivaled in Liyue, yet he works as a mere employee of an eccentric young human lady. That factor partly helps offset the imbalances between Hu Tao's and Zhongli's standings.

Hu Tao is often portrayed as the dominant/assertive one in their relationship, which is one of the major appeals of this ship. Having a whimsical young human girl pranking/bullying the solemn Geo God of Liyue who is helpless against her for some reason - gap moe and hilarity ensues.

From its inception, Hu Tao/Zhongli ship has spawned the most user-generated contents (fan arts, memes...) in total among all of ships which involve Hu Tao.

It should be noted that Hu Tao playerbase overlaps big time with Zhongli playerbase, so it's expected that those players would feel attached to those two characters, as well as tolerating the relationship between them.

It’s also common for people to view and portray the relationship between Hu Tao and Zhongli as found family.

One of the most common themes of Hu Tao x Zhongli ship is the opposite of the romantic comedy theme mentioned above: angst, and it's partly thanks to the nature of Hu Tao's and Zhongli's jobs (as well as their associated connotations) at the Wangsheng Funeral Parlor.

Trivia

 * Seiichi “Sen” Takahiro - Art Director and Lead Character Designer at miHoYo - has drawn an artwork titled "Zhongli x sh