I forget the title of this manga I read couples years ago. It's about acting. The tricky part, I don't remember the MC or much of it. In general, the MC's likely the producer or the acting coach, and in the arc where I stopped, he coached this dude, who used to be a star, into a yakuza role by making him live the yakuza life for a time. He aced the role so hard, it left a strong impression and got me hooked on old school gangster movie. I really want to know now that I think about it. Any response is appreciated.
The only acting ones that come to mind are Glass Mask and Skip Beat, both of which don't match. https://www.anime-planet.com/manga/tags/acting?page=1 Maybe you can see if it is on the list here.
None I'm afraid, tried looking at all other suggestions and the manga listing. No dice. Ashamed that.