Seiyon
If you are going to make the company that sells manga and everything related to novels, it would not be better also to have a studio where you can produce anime, movies, also as I said you can make it create or buy a studio or company related to singers (idol ), in general you have companies related to the production of novels (so you can manage better and earn more xD). - You can also as you mentioned clothes, you can sell "cosplay" clothes from what your company produces, and don't forget to also create games (minicraf, pokemon (which is popular for all ages)). - you can make your protagonist take over everything related to entertainment and eventually becomes the "CEO" with the most companies in the world.
resien is the beginning of the protagonist having fun in the human world. - A question, it would not be fun if you introduce the novel (Arifureta Shokugyou), where you make the protagonist go to the other world and have fun conquering the countries and in passing killing the "false god", of course without forgetting to add the milf that there are , and some girls who are interesting. - Also don't forget that you can also put "pov" for a change and see what others think of the protagonist, etc.