^ They are leaders of East(Kanagi) and West(Yachiyo), their involvement in the past is almost entirely political in nature, they are friendly towards each other but you have to squint real hard to get anything resembling romantic context out of them...
Comparatively, Kanagi and Mitama are best friends, something you actually wouldn't know without having seen Mitama's personal story, they go to the same school(despite her looks and demeanor, Mitama is only 17, she is still a high schooler) and even the same class room, and Kanagi played a vital role in Mitama's life immediately after the latter contracted, as Mitama was going through a lot at the time and was very close to Witching out immediately... I am not saying I ship them at all, I don't ship Kanagi with anyone really, but rather explaining that if you are really looking for a connection between characters, that's where you'd most likely find it.