You write an unpublished short story and send it to me for my comments. I like the plot and setting so much (and i tell you so) that I decide to rewrite the story, retaining the setting and the plot but slightly modifying the characters. In a nutshell, my version is your story played out with somewhat different characters. I send you my version for your approval. I have no intention of publishing that story as my own, and you know it. My only aim was to try my own writing skill and hope to receive your comment.
You do not agree with certain attributes I have assigned to my characters, for they do not fit in with your own vision of them and their background, of which you have not given any clue in your story. You try to persuade me that my characters are flawed as they do not meet with your ideas about them, and do not fit in the cultural setting you have in mind. We both stick to our guns, and you ultimately accuse me of deliberate plagiarism, knowing fully well my intention in rewriting your story.
Does the above make me a despicable plagiarist?