Ishikuro

Canon
In the game, they barley had any interactions, since Mukuro was disguised as Junko. As the stpry progressed and they reveal Mukuros talent, Ultimate Soldier, people started shipping them because of the talents, as Ishimaru was the Ultimate Hall Monitor/ Moral Compass.

Fanon
People ship this because of talents. The way Ishimaru is strict and Mukuro is also strict give people another reason to ship IshiKuro. Shippers of this ship feel like if Ishimaru saw Mukuro, they would have a connection, other than knowing Mukuro as not even Mukuro, and in a Junko disguise.