This is definitely an adaptation. I'm guessing the original had some sort of lore dump to explain what the hell is going on? "Oh you're in another world! Now get to work." The protagonists don't seem to ask questions, or react in anything resembling a reasonable manner at having been press-ganged immediately after death. Or react to "mercenaries" essentially being slaves but it's okay because demihumans aren't people and it's for their own good, and you can buy them if you earn enough mercenary fun bucks. Fffffuuuuck. Nobody even tells us what Labyrinth Country is. Are there non-Labyrinth countries? Does Labyrinth Country have a constitution or borders, or currency for non-Seekers? Is it a world or a part of a world or a dream? If they work long enough do they get to die for real, or since they died already do they just keep working forever? Is this a metaphor for capitalism?
The art is good, the character design is good. The dialogue is kind of okay... But there's nothing there. It's mimicking DanMachi and Sword Art Online in basic plot structure, where the female characters are put through the emotional wringer and rendered powerless by an unjust system or systems, allowing this story's generic male protagonist to save them (or fail to save them) in their darkest hour using a loophole in the poorly-explained game mechanics and a helpful does of plot armor, but unlike those successful series, the protagonist is a philosophical zombie lacking any identity of his own. The "emotionless" slave girl harem member has more backstory than the main character, and that was spat out in two chapters, one of them a bonus! Despite following Salaryman for ten chapters we know nothing about him or why he's doing this because there is nothing to know, he exists to be projected onto as he reacts to the plight of the women around him in absurd ways. He has no family or friends or hopes or dreams, only his mind control/corruption powers, which are really creepy, and get even creepier as harem members get younger.