I'm writing what I believe is an INFJ and an ISFP character duo. Let me explain a bit about their dynamic, and I would like some insight if available:
In my story, the INFJ character is undergoing an emotional crisis that is leaving her insecure and depressed. She can't stop thinking about her cause (to use vigilante justice to help others. I know violence isn't really an INFJ thing, but this is how the character was raised, almost as if she were being forced to embrace her Tert Ti and Inferior Se in an ISTP kind of way). She worries that her ISFP friend doesn't care about her cause, and therefore doesn't care about her. However, she doesn't really express herself very well (not related to her type, but rather her troubled past and lack of self-esteem), and she also doesn't directly voice her concerns to her ISFP because she doesn't want to hurt her feelings.
The ISFP is a little more upbeat than her INFJ friend. She pretends not to be bothered by things because she doesn't want to burden the INFJ with her own emotions. At the same time, she's trying to pull her INFJ friend out of her moody depression by trying to get her to enjoy the littler things in life. She worries the INFJ doesn't care about her as a friend, but keeps her personal deeper feelings very guarded and doesn't want to create any conflict.
With that being said, I have a few questions about an INFJ and ISFP dynamic. What might their friendship be like? Who would initiate things? What sort of shenanigans may occur based upon the differences in their NiFe and FiSe views on life? Might one appear more extraverted or pragmatic than the other? How would they contrast with eachother?
Don't be afraid to share personal anecdotes or random conjectures, if you have any; I myself am an INFJ with a close ISFP friend, but I don't think I'm in an objective enough position to gather insight from our own perspective.