Caikong

Yukong/Caiyi is the femslash ship between Yukong and Caiyi from the Honkai: Star Rail fandom.

Canon
Yukong and Caiyi were childhood friends with a passion for piloting starskiffs. When they first met, they were rivals racing each other on starskiffs. But soon they became friends, a pair of troublemakers that got into trouble with General Jing Yuan a few times. In adulthood, Yukong and Caiyi became pilots participating in the Abundance Wars. Yukong and Caiyi become flight partners, something they were very glad about. The two worked exceptionally well together, better than even Caiyi when paired with her husband Guangyuan. Yukong was like a "flaming wind", with the only one able to calm her being Caiyi. The two also wrote to each other in exchange diaries.

Yukong and Caiyi worked together for over a hundred years by the time Caiyi's husband Guangyuan died. Yukong was always uncomfortable with Guangyuan and didn't like seeing him and Caiyi close. Despite this, she was saddened over his death and worried that Caiyi was pretending to act strong in her grief. Caiyi assures her that she is satisfied that Guangyuan died happily, as a hero.

At some point, Caiyi goes on maternity leave. In the exchange diary, Yukong confides in her, saying she has only recently realized the brutality of war and that she is hesitant to form connections with other people. She also asks Caiyi not to name her child one of the bad names Guangyuan chose. Caiyi agrees and goes with Yukong's idea of a name, "Qingni." Following Qingni's birth, the situation in the war is starting to become uneasy, so Caiyi prepares to return to battle with Yukong in the following weeks.

Before entering battle, Caiyi writes that if she dies, she wants Yukong to take care of Qingni like her own daughter and support her, but to never let her become a jet fighter. In the battle, their ship ends up getting hit, fatally injuring Caiyi. Yukong holds her in her last moments, begging her to wake up. Caiyi requests her not to let Qingni become a pilot, a promise Yukong would faithfully keep. After Caiyi's death, Yukong never piloted again.

Children
Qingni Qingni is the biological daughter of Caiyi and Guangyuan, and Yukong's adopted daughter following their deaths. Yukong picked Qingni's name, the colors of dawn, which she chose after going through several poems. Caiyi's last wish was for Qingni to never become a pilot, yet Qingni grew to be as talented at flying as her mothers. It became her dream to become a pilot. Yukong never told her much about Caiyi, but was steadfast in maintaining her promise. Yukong would be uncharacteristically unreasonable whenever the subject came up. In an effort to understand Yukong's motivations, Qingni reads the exchange diaries, discovering her true origins and why Yukong was so adamant on her not becoming a pilot. This allows the two to have a heart-to-heart, and Yukong eventually accepts her daughter's dreams.

Quotes
"Yukong and Caiyi trusted each other with their lives."

- Jing Yuan

"Of course I missed you! The galaxy felt smaller without you in my cockpit..."

- Yukong

"In my dream, that was the day I died."

- Yukong about Caiyi's death

Fanon
Before Caiyi name was revealed, her character was known from the lightcone "Past and Future" in which a dead "beloved" of Yukong is mentioned. Details about Caiyi and Yukong's relationship were leaked in June 2023, which fans quickly connected with the "beloved" mentioned in the lightcone. Many interpret their relationship to have intentional romantic subtext.

Some interpret Yukong to have an unrequited crush on Caiyi, as Yukong's negative feelings towards Caiyi's husband could be interpreted as jealousy.

Fandom

 * TWITTER