If you're looking for manga similar to Franken Fran, you might like these titles. All recommendations are made by Anime-Planet users like you!
Yucy and Yudy are two conjoined twins who have been together since birth. However, as the nutrients in their bodies distribute unevenly, Yucy is beautiful yet slow-minded while Yudy is intelligent and horrifically ugly. Yudy is torn between her love for her sister and her hate for having to care for Yucy; can the two continue to co-exist?
There's no guarantee that you will be happy with the one thing you've always wished for.
Call it a gut-feeling rec, but Hanshin feels like it could be a chapter from Franken Fran. Despite the lack of nudity, gore, and medical jargon, Hanshin sports the same twisted mentality/morality and life-altering surgery as Franken Fran.