oh this... this is a very old question, i am so sorry. it's probably fairly obvious, but i primarily associate the domans with koharu because she IS doman. she grew up as friends with hien and yugiri (albeit a little older than them) and considered gosetsu to be like a grandfather. yotsuyu she has very complicated feelings about because koharu considers her to be a "what i could have become" scenario, but also yotsuyu very much represents the culmination of koharu's own mistakes because she was just as responsible as the rest of doma for what yotsuyu became. it's not something i've really 100% decided on being canon or not, but i've been thinking a lot lately about how there was a chance she knew yotsuyu and asahi as children, which would have greatly impacted her (and her interactions with both of them) in the far eastern arc in stormblood as well.