Kujou Family. They’re based in Kyoto which was the former capital before it moved to Tokyo. And because of that, the noble lineages based there could be said to be the elites of the elites. They’re closest to the ones in power and oftentimes, they would have blood times to them.
According to my mother, while the Kujou Family also got hit by the recent abolition of the noble cliques, their influence remained not only in the government but also in the elite circles that normal people would have no knowledge about.
Marika is from the main branch but not within the direct lineage. Her father is the younger brother of the current Patriarch. He’s kind of an ambitious man who’s probably scheming to become the head or at least, have the sway to the decision-making of the whole clan. Tying her with the Ichihara is one way for him to have another chip on the table.