Kaguprez

Kayuki is the het ship between Kaguya Shinomiya and Myuki Shirogane from the Kaguya-sama: Love is War fandom.

Canon
The main premise of the series is Kaguya's and Myuki's romance. They are both in love with each other, but are too petty to admit their feelings openly, seeing a 'confession' as an absolute loss that must be avoided. Until chapter 136, the two remained in a constant stalemate of getting the other to confess to them.

Following the Cultural Festivals arc, Kaguya and Myuki have offically started dating and have kissed a few times. By the recent chapters they have grown extremely intimate with one another.

Fandom
It is one of the most popular ships in the fandom, as it's the central romantic plot of the story. Anime fans and manga readers all well aware of their relationship. As such, many fanarts and comics have been made throughout the past year, when Kaguya-sama's popularity exploded.