Basic Trope: In order to show the world that minority characters are not bad people, one will step forward to help a "normal" person, with their pure heart and folksy wisdom. They are usually black and/or poor and are often there solely to help out the white main character.
Straight: Joey, the CEO of Tropecorp, is given moral advice by Ramell, the black night janitor, which helps him save the company and restore its ruined image.
Exaggerated: Joey, the CEO of Tropecorp, is unable to function in his role without the advice of Ramell, the night janitor.
Downplayed: Joey overhears Ramell giving someone else advice, and he decides to try it out, too.
Justified: Ramell has a high IQ, had a good, moralistic upbringing and reads a lot but comes from such a poor background that he had to start work straight after highschool. As such his talents have not been put to good use.
Ramell's advice causes Tropecorp's stock to plummet and Joey to lose his job.
Ramell demands a better job in exchange for his wisdom.
When Ramell is off-duty, the story switches to a subplot that explores conflicts of his own.
Ramell and Joey are both black.
Double Subverted: However because of his policies giving him a reputation for moral business practices Joey is able to use his severance package to start a new company, Tropes inc, that both outperforms the dying Tropecorp but also has a very positive public image.
Ramell is able to answer any question put to him, no matter how complex or niche, from "What is beauty?" to "How do I build a faster than light space ship?", in the form of folkey proverbs and idioms.
A spotlight appears on Ramell, or he otherwise glows, when giving advice.
Ramell is a literal magician, as well as wise.
Zig Zagged: Joey sometimes gets good advice from Ramell, sometimes bad. Sometimes Joey ignores the advice, and sometimes he gives Ramell advice.
Averted: Ramell the night janitor is about as astute as to the workings of the world as you would expect him to be.
Enforced: "That black janitor was reading philosophy texts earlier, clearly he is the one Joey needs to speak to".
Lampshaded: After asking Ramell for advice Joey says "Why the hell is that guy working as a janitor?".
Invoked: Joey: "What I need right now is a poor, ill-educated, black man".
Exploited: Joey hangs out in the park all day, confident that the moment he lets his guard down, a poor black man will show up and begin dispensing wisdom.
Defied: Joey: "What the hell does that guy know anyway?"
Discussed: Joey: "That's all well and good Ramell but I think I will go with the consultants I have on 6 figure salaries".
Conversed: "What's going to happen here is the principled and moralistic poor black man will tell him what to do and he will ignore his consultants".
Deconstructed: Ramell realizes how valuable his advice is, leaves his janitor position, and gets Joey to give him a well-paying job in Tropecorp's public relations department.
Reconstructed: Ramell's character is developed by exploring in detail why he would want to help Tropecorp and why he would not want to leave his low-paying position.
Played For Laughs:
When Joey asks Ramell for advice, he responds by saying Joey should go fishing. This works.
Joey is trying to make a difficult decision. He asks himself if the solution to his problems is to change the way he's running Tropecorp, or business as usual. Ramell walks up to him and says "Change?" Joey thanks Ramell, embraces him, and runs off. Ramell, confused, mutters "I only wanted to know if he could break a dollar."