How do I structure multiple characters stories?

I'm creating a game in Unity. It mostly involves character interactions. So if I'm interacting with a character, then I go do something else, possibly interact with other characters, when I come back to the first character, I want to pick up where the conversation left off. I currently have each character's story in their own knot. Right now I only have 1 scene and my solution is working for the most part. I'm not quite sure what I'll do yet when I add a second scene.

Also I'll be tracking stats on these characters, similar to a reputation system, where different dialog options will open up based on your reputation with that character.

I'm wondering what the best way would be to structure this type of story in ink.