It's just my large pet peeves around how the story/characters wind up being portrayed. Plus lots and lots of little tidbits that get under my skin.
We have our main character, who's just utterly stoic and unrelateable. He's this socially defunct gamer stereotype that's placed into the role of HAVING to be a lady's man or suffer painful death. That's actually an alright premise, you can actually squeeze some entertainment out of that... but what winds up happening is that he treats real life LIKE his videogames, and he only succeeds because the narrative refuses to allow him to fail. It's just utterly bizarre how stupid and how lifeless he can be, and people still wind up getting attached to the guy, and the show makes the leap and he becomes utterly detestable with how unable he is personally to get attached right back. It's preposterous watching the ending credits, and how it involves all the relatively interesting girls he's wooed so far dancing around in paint to create a giant mural of his own goddamn face, which is just emotionlessly glaring at the camera.
We have his sidekick character, who is there to set up the plot and then she serves no purpose or consequence whatsoever. It's like they just needed her to get the ball rolling, and then they want to throw her away, but can't out of some narrative obligation. Shit, she's supposed to be a literal magical demon from another dimension, but it almost never comes up! That sounds like something that's interesting, but it's like "Doy, let's just watch our POS hero play vidyagames or something! That's what the kids today want to see!". Like, really, that was... not one, but TWO entire episodes, just watching the MC play videogames. REMEMBER THE PREMISE? REMEMBER HOW HE BECAME INDENTURED TO LORDS OF HEAVEN AND HELL INTO BECOMING A MALE GIGOLO? I DON'T EITHER.
This is only the first season mind you though, so only the first 12 eps apply here, but you can clearly see that on the 12th, the creators proudly announce that it's getting another season! It's like they had to contain everything into these stilted and uncomfortable mini-arcs because they THOUGHT that was going to be it, but inexplicably caught enough attention to get people clamoring for more.
Plus it bothers me that one thing that happens very early is that the Sidekick walks into our MC's home, tells a blatant lie, gets his parents divorced, and then nothing ever comes of that again. SHIT MAN I think having your family broken up by a literal demon would have earned a little bit more attention. But nope, MC doesn't care about his father at all, the loss of one of his parents means nothing, OKEYDOKEY!... Fuck...