hard to say anything unique... I imagine Kanako with a texan voice due to a good friend. Suwako would sound a little southern too, but more like an Old person. Also! Kotohime would probably get into Sanae's cool stuff like video games or anime and also just probably have a bunch of her own cool stuff in the bedroom somewhere
I imagine Kotohime could be watching Sanae's stuff in her room while Sanae's out while giving the excuse that she's tidying (She DOESN'T KNOW HOW TO TIDY. BAD LIE)