I have come across this kind of issue recently.
And, mind you, this subber has an excellent command of English, it’s obviously someone very experienced, who has been living in the US for a long time - probably even born there. So there are almost no grammar and syntax issues, and the following style choices are most certainly deliberate. Just that they don’t match well, they “sound” fake and inappropriate.
For starters, all names and surnames are reversed, in a Western way. Everybody is Mr. and Mrs. This person has probably never watched a drama on Viki, so they did what Western platforms like NF do.
A Japanese executive goes to a farm in the countryside to solve a produce supply problem, and when he has a few drops of liquor, he displays drunk behaviour. The choice was to make him speak like an inner city US citizen.
“Pops! You were so worried 'bout your missus, yet I forced ya to the farms.”
And, to his co-worker:
“You’re a good kid. But ya know what? That don’t mean she’ll see ya as a romantic interest. Too bad for you, kiddo.”
Probably the character is talking colloquially in Japanese as well, in a way that clashes to his usually composed self, so this was a “domestication” choice, to give the same comical impact and get the same reaction from the viewers. Yes, but the fact is that on Viki not all the people reading English subs are American. And even if they are, that language is so specific to a certain part of the American population, that it seems super-weird in a Japanese mouth.
The following screenshot shows a Japanese university professor talking to his PhD student. (And he’s not drunk)
Again, the professor in this scene a bit surprised/distressed so he is probably using a more colloquial Japanese expression, in which case this was a deliberate choice. I’m pretty sure that’s the reason. But to localize it to American slang is not the way to go, in my opinion.
What should be put instead? I don’t know the source language, but I’m sure one could find a more colloquial way without going to the extremes of using American slang.
But the whole drama is peppered with “gonna, wanna” and all those things we specifically mention on Subbing Guidelines NOT to use. And the general tone is like this.