About the novel of kakashi and tsunade:
I think you are the only one who writes about this duo, I have been looking for a novel for a while that combines my favorite character Kakashi with a beautiful woman like Tsunade and the idea that you are the only one who writes this kind of romance between two famous characters is a very wonderful and motivating idea.
My advice is not to change the personality of the characters and keep them the same as in the anime. Don't rush to add romance at first, wait until the readers get used to the novel, then add touches of romance and deviation , and don't forget about jealousy, I'm sure that your novel will be great if you complete it, you will be really proud of yourself, don't forget that there are people waiting for your update