not to mention, there's a moment in the manga where Mugi was on a call with Mio, and Mugi was mad to someone named "Saitou" for cutting in their phone call....could it be?
Ryuamakusa4eva said: not to mention, there's a moment in the manga where Mugi was on a call with Mio, and Mugi was mad to someone named "Saitou" for cutting in their phone call....could it be?
It could also possibly be one of Sumire's family members. I get the impression she's from a family that has traditionally served the Kotobuki family for a long time.