If you are making a neodoujin type project based heavily on another project, it is polite to reach out to the creator of the original project and let them know your intentions. This can open up a door for you for marketing and collaboration.
It is impolite for a creator to be blindsided by the release of a project that has in some major way cited / remixed / recontextualized their project. The original creator can know nothing about it while others may be asking them about it which puts the original creator in a compromising position. That is not to say that when you make a remix or use heavy citation you are obligated to inform the original creator of your new project, but that you may have better outcomes when your remixed / citational projects have some advance awareness by those they are remixing / citing.
It is strongly recommended that you give a % of your withdraw and royalties to the original creators of your neodoujin remix sources. This share can be done with moneypipes, and you can ask the original creator which address you should assign their share to. This can be as low as 5% or as high as 50%, we recommend 30% for projects which heavily draw from another neodoujin type project. Giving back is ethical and highly recommended.