I think that's the point is that it's tongue-in-cheek
Like you can't say that this ISN'T over the top to the point where it's ridicolous given that the first two pages has him stab the over-the-top evil guy WHILST WEARING THE FACE OF SOMEONE ELSE. LITERALLY.
And then the preceding "Cool guys don't look at explosions" shot.
Also this is SUPPOSED to set up that he's a clever and effective killer, but this is contradicted EXPLICITLY later.
Not to mention, they clearly just inserted a photo of a 100 dollar bill because they were too lazy to draw it and just put a dynamic background to make it look cool.
Also, there's the over-the-top reaction/joke about him instantly getting a the bank girl's number because she found out he has 20 million dollars despite the fact she hated him before she discovered this fact.
Also, this tactical and cunning hitman apparently puts down all his defenses when he sees attractive women. Not only is this principle non-nonsensical as someone like him should not be as easy to manipulate given his vocation, but also the author is very wishy-washy about this. He only pretends to flirt with the bank teller and then destroys her number and he doesn't seem entranced by the woman he's working for in the slightest. Yet, somehow, he's immediately seduced to by a several-million dollar home because some nice real estate agents made his dick hard and he lets a random girl, whom he does not know, into his home, and she gets the jump on who is supposedly one of the most brilliant assassins in the world. He's so inconsistent it's funny.
I think the best argument you can make is that this manga is meant to be the equivalent to a B-Movie that's so stupid that it's enjoyable as it embraces its own campy nature.
@ctn