Edit: it's just a one-shot promo for the novel:
https://www.novelupdates.com/series/survival-rules-for-d-rank-guides/
As of 8/13/24, novel was dropped in translation and the existing chapter links are dead.
Summary:
"In a world where gates suddenly appeared, Espers were like a national power. South Korea's representative S-Class Esper, Cha Jaewoo, had a problem: after he gained his powers, he couldn't find a guide who had a high match rate with him.
Thus, it was mandated that all citizens must take the guide test.
"No way... I really hope this is not the case, but..."
"Haa..."
"...Is it Cha Jaewoo?"
Haeyool took the test, thinking he might as well get it over with, and he set a record of an unprecedented 97.8% match rate with Cha Jaewoo!
"So what? I'm a D-Class...!""
Not licensed in English. From what I can find, it's finished at 147 episodes in Korean (novel only? Unsure), so sad because even though it's a common premise, I never get tired of it. Neither of the scanslation groups that worked on it seem to have any intent to do more of the story.
Series info:
https://www.mangaupdates.com/series/9gbu9g0/a-survival-guide-for-d-class-guides
1st: 6/4/23, 2nd: 4/13/24 (it truly is just a super short trailer, no need to read again unless maybe you find a working link to the novel or it gets serialized)
A Survival Guide for D-Class Guides