Zenhee

Zenhee is the het ship between Hyun Ryu and Jaehee Kang from the Mystic Messenger fandom.

Canon
On the casual route, they talk on the messenger sharing friendship and, normally from Jaehee, appreciation. On Yoosung's route, they continue being great friends. On Zen's route, they are also friends but Jaehee gets distant because of MC's actions.

Although, on Jaehee's route, they seem to be really close, especially when Jumin gives her more work and Zen gets pissed. They start hanging out, sharing gifts and, it is during her route that we see the most famous quote from the ship: "I will be your number 1 fan".

On Deep Story and Another story, they continue as friends.

It is hinted a lot of times that Jaehee likes Zen as more than just a friend, but she always denies it by saying that a relationship with an actor could ruin their career.

Zen doesn't seem to be romanticly interested in her on other's route, but on Jaehee's route he cares about her deeply, also they go out on what seems to be like dates.

Fanon
Jaehee is in love with him and during her route, they get closer and closer to the point he falls in love with her. Zen doesn't care about his career, he just wants to be with the love of his life.

Fandom
The ship isn't that popular due to the fame of Jumin x Zen. On Wattpad, there are only a few stories about them. The most famous one (based on the number of reads and kudos) is "Cooking With Love", a bunch of Zenhee one-shots. The artist @pinka_lala on Tumblr makes most of the fanarts of the ship.

Trivia

 * Jaehee seems to have a semi-canon crush on Zen.
 * Zen didn't think that Jaehee was his fan at first.
 * Jaehee has a fangirl account.
 * Jaehee almost joined a hate group for Echo Girl.
 * The spaceship reveals that Jaehee was a photo of Zen on her mouse pad.
 * Since Jaehee's route ended up with her and MC being 'gals being pals', a lot of shippers consider that sometime after the events Jaehee and Zen actually end up together.