Kiamei

"Because we understand each other, I know what her decisions would be, and it's the same way around, and none of this is going to be changed by how far we're apart or how different our positions are."

- Mei to the 10th Herrscher about her and Kiana

Kiamei is the femslash ship between Mei Raiden and Kiana Kaslana from the Honkai Impact 3rd fandom.

Canon
Mei and Kiana are both teenage students who are training to become Valkyries together at St. Freya High School. They're part of the main trio in the game along with another younger girl named Bronya Zaychik. Kiana is very open towards her attraction to Mei and insists that she loves her back. A lot of the time she will blatantly flirt with Mei and carry on with perverted comments or actions to do with her, even in serious situations. Mei usually doesn't mind Kiana's actions as long as she's able to contain her public displays of affection. But after their separation, it was clear that Mei missed all of Kiana's public displays of affection, and was baffled when the Kiana she met in Arc City was not the Kiana she met in St. Freya anymore.

Nagazora Eruption 2014
They first met in the year 2014 when a Honkai outbreak took place in Nagazora and turned many into zombies. As one of the survivors, Kiana made her way to her school's rooftop for safety where she met a senior student named Mei Raiden. She turned out to be a Herrscher, but her human conscience appealed to Kiana so they fought as she tried to save her. Once Mei gained control of herself again, she tried to jump off but Kiana grabbed her hand and pulled her back up with a smile, resulting in the Herrscher deciding to hide away in Mei's heart because she could tell her host cared about this girl. From there on the two became close friends as they tried to escape their school together. Later on, Mei thanks Kiana greatly for saving her life, which is also when Kiana calls her cute for the first time.

The two later met Bronya and the three attempted to escape the decimated city. During this time, Kiana was gravely injured by a Honkai beast which reawakened the 3rd Herrscher in Mei. Under the influence of the 3rd Herrscher and cradling Kiana’s unconscious body, Mei destroyed the Honkai beast that injured Kiana. This caught the attention of Himeko Murata, a Schicksal Valkyrie. The two duel each other and during the duel, Kiana woke up and destroyed Mei's Herrscher wings, bringing Mei back to her senses. Afterward, the two were later taken to St. Freya High where they train to become Valkyries and protect all that is beautiful in the world.

AE Invasion
During the events of AE Invasion, Anti-Entropy attempted to kidnap Mei and during the kidnapping attempt, Mei fell unconscious. The 3rd Herrscher later awakens and battles the kidnapper (a clone of Welt Joyce, the 1st Herrscher). During this time, Kiana is in a training simulation with Theresa Apocalypse. Upon hearing that Mei was in danger, Kiana attempted to leave and help her. The two of them work together to defeat the Welt Joyce clone which leads to Mei powering up Kiana's battlesuit and their dorms being destroyed.

St. Freya
The main story begins in 2016 with the main trio being tasked to recover a battleship called the Selene. During the events of Chapter 1, Kiana saves Mei from a Honkai zombie about to attack her and the 3rd Herrscher within Mei saves Kiana from a horde of Honkai beasts. Later, the trio returns to St. Freya to take the yearly Valkyrie Examination exam where during one of Kiana's nightmares Sirin calls Mei Kiana's girlfriend (though this was later changed due to censorship).

Sometime later, the trio is sent to New Zealand to recover the Gem of Desire, which has been placed inside an ex-Valkyrie named Wendy. Wendy soon lost control and became the 4th Herrscher. The three are forced to fight her and during this situation, Anti-Entropy suddenly appears. They ambushe them using a brain chip placed within Bronya and both Mei & Wendy were captured. This leads to a rescue mission where Kiana attempts to save Mei. During the rescue attempt, Bronya sacrifices herself and falls into a coma to save Mei. This devastates both Kiana and Mei.

Battle of Schicksal
Once again, things turn for the worst as Otto Apocalypse abducted Kiana and reawakened the 2nd Herrscher (or Herrscher of the Void) within her. To save Kiana, the Far East Branch of Schicksal teams up with Anti-Entropy to defeat Otto. When Mei suddenly reunites with Kiana during the Battle of Schicksal, the 2nd Herrscher defeats Mei and takes the Herrscher core within Mei for herself. The removal of the core causes Mei to fall unconscious.

This part of the story ultimately ends in the 2nd Herrscher causing another Honkai eruption and devastating the planet, while Mei & co. become fugitives on the run.

Arc City
After a timeskip of four months, the group consisting of Theresa, Bronya, and Mei (Himeko DIES and Kiana goes missing by the way) head there to see if they could find any sightings of Kiana. The three find the Ningyo, a cyborg who might have information on Kiana’s whereabouts. However, Rita Rosseweisse, a powerful Schicksal Valkyrie ambushed them and resetted the Ningyo before anything could be found.

The team later split with Theresa and Bronya heading to the Deep while Dr. Telsa and Mei went to repair the Ningyo. The Ningyo suddenly rebooted and Rita reveals Kiana’s location. However, Kiana was kidnapped by the World Serpent, a mysterious organization with suspicious motives. Rita contacts Mei for support and goes back to Arc City. The two reunite and Mei asks Kiana to return to the Hyperion. Kiana, however, could not go back. It turns out that the World Serpent has been planning to cause a Honkai eruption in Arc City to move towards their goal of enacting Project Stigma.

In the end, Kiana had to send the Honkai bomb that was supposed to denote in Arc City away, letting it denote in the sky instead. Kiana passed out and fell from the sky. Mei rushed to save Kiana only to be stopped by Durandal, the most powerful Valkyrie in Schicksal. Durandal brought Kiana back to Schicksal, and Mei couldn’t do anything about it.

Thunders Over Nagazora
During a World Serpent ambush at the place she was imprisoned, Kiana managed to escape and makes it to Nagazora. After detecting the energy fluctuation, Dr. Tesla also took Mei to Nagazora to reunite with Kiana once again. Mei also meets Raven once again and the two work to find Kiana, yet it turns out Raven’s motive was to kill Kiana. The two fight, though without her Herrscher powers, she couldn’t do anything. Regardless, Mei tried to stop Raven and started concentrating Honkai energy in her body. She defeats Raven and went to find Kiana once again. This time, however, it would not be the same.

Due to all the Honkai energy within Kiana’s body, she only had at least 2 months to live. This news devastated Mei and she found herself unable to do anything about it. The leader of World Serpent, Kevin Kaslana notices this and makes a deal with Mei: World Serpent could save Kiana if Mei becomes a Herrscher again and join them. Desperate to do anything to save Kiana, Mei gladly took the offer.

Kiana fought Mei in a desperate attempt to have her stay, yet in her weakened and dying state, she couldn’t do anything. Mei wins the fight and the two parted ways once again.

Herrscher of Domination Arc
As the puppets separate Mei from the theater to prevent her from finding out their true goal (which is to awaken Herrscher of the Void and make Kiana and Herrscher of the Void fight for absolute control of K-423's body), Mei fights with countless puppets just to get out of the illusion and back to the theater to be able to assist Kiana as Mei is aware of her presence yet at the time Kiana wasn't. As it dawned on Mei that her fully awakened herrscher power (called Conquest) is stronger than that of Domination and Reason (Reason is what Herrscher of Reason's - Bronya Zaychik - power is called) combined, she used this opportunity to be able to weaken the puppets by a lot when she slashed them down with multiple thunders accompanying it. The effects of Mei's attack caused thunders to strike down and it startles Kiana as she was staying in the fragmented space created by the Gem of Haste along with Himeko, and at this time Himeko tells Kiana to leave and defeat the Herrscher of Domination, and when Kiana got out, Bronya and Fu Hua inform her of Mei's assistance from somewhere in the theater.

Kiana acknowledges this, and is grateful as she knows that Mei is there to fight with her albeit separated by the fragmented illusions of the theater.

Fanon
Kiamei is the most popular ship in the fandom and the most well known outside the fandom. Some players even state that if miHoYo does not add Kiamei into the 4th game, they should at the very least let them reunite, or give a bittersweet ending and state that if the two would get a bad ending they would quit the game. Some people might dislike the ship because they see it as "overrated" or think that Kiana is annoying and clingy. Some may even go as far as describing some of Kiana's actions towards Mei as harassment. Though as the story continues and the characters keep growing, there's still many chances for more people to come and like it, especially as their characters develop more (i.g. Kiana maturing, and Mei being more aware of who she's really fighting for).

It is the most written about ship on AO3 with FuKi (Fu Hua x Kiana) and Bronseele (Bronya x Seele) coming in second and third. This is the most trending ship in the Honkai Community with FuKiMei (a fanon ship consisting of Fu Hua, Kiana, and Mei) and BronSeele as 2nd and 3rd.

Fandom
FAN FICTION

Quotes
"I always believe in Mei. We're the best of partners, after all."

- Kiana's Herrscher of Flamescion battlesuit bridge lines "The night is so quiet... I miss her."

- one of Mei's bridge voicelines about Kiana in the Herrscher of Thunder battlesuit "I like how you, at the end of every mission, would kick down the dorm door, and shout "Mei, I'm home!", and then leap beside me and yell about how hungry you are... I would always rub your hair and tell you... "Welcome back!" I like all these about you."

- Mei, Chapter 8 about Kiana

"I don't need to go back to the past. Neither does she."

- Mei, Chapter 25

"If rescuing you is a sin, I'll gladly become a sinner."

- Mei, Lament of the Fallen Animated Short

"Sorry, my lady. I've kept you waiting. Have no fear! Kiana the young knight is here!"

- Kiana, AE Invasion Chapter 13

"You said you were alone. I used to be alone myself. Two ex-loners make the perfect team."

- Kiana, Chapter 16 flashback to when they first met

Trivia

 * They're both Herrschers; Mei is the Herrscher of Thunder and Kiana is the Herrscher of the Void and Flamescion.
 * Kiana loves food and Mei is an excellent cook.
 * In the game, there is a stigmata named "True Love Forever", which has art of Kiana in a tuxedo holding Mei who is in a bride outfit.
 * Kiana is often compared to a tuna as a joke by fans and developers of the game. Because of the joke, MiHoYo added in-game weapon which can be equipped on Mei named "One Salty Tuna".
 * In a manga which was later decanonized, there was a scene where Mei was worrying about Kiana and had a dream where they got happily married, only to result in Kiana dying before her eyes.
 * The trial character of White Comet (W.C.) for Chapter 17, (Thunders Over Nagazora) in the stage where Kiana and Mei fought before Lament of the Fallen (name of the animated short), W.C's stigmas are shown to have Mei stigmatas, namely; Mei: Princess (T), Mei: Bride (M), Mei: Birthday (B). See gallery for the picture.
 * In Gun Girlz/Honkai Gakuen 2 (the predecessor to HI3rd), at the end of the main story God Kiana asks if God exists and that if God does exist, let her and Mei meet again before the world resets.
 * In the Xuanyuan Chronicles, Kiana mentions having a cat named Sora. Mei believed Sora to be another girl and Bronya comments on how she "detects jealousy" which lead to Kiana having to clarify that Sora was her cat.
 * In A Post-Honkai Odyssey, an open-world game mode set eight years after the main story; says that 99% of Honkai energy is sealed on the moon, Mei's introduction states that "she is anticipating a reunion with someone special", clearly referring to Kiana. As Kiana was said to be "MIA" and it was hinted that she sealed herself on the moon along with 99% of Honkai Energy and Mei was noticed to be always looking at the moon as the APHO main character's dialogues regarding Mei said.
 * The canonicity of this game mode is however up for debate since miHoYo flips back and forth between "canon" and " non-canon" often, stating the lines "APHO is in the same worldline". So it is muddled as of now whether it is canon to the main story or not.
 * In the 2017 White Day (March 14) there were official tokens added in-game wherein two rings were seen. Namely, "cat's claw ring" which is a ring given by Mei to Kiana, and "bow ring" which is given by Kiana to Mei. The selling price for the cat's claw ring is 520, while the bow ring 1314 in-game currency. In Chinese, 520 = I love you, 1314 = forever (forever). See gallery for the picture.