the artstyle is...unique ... I can understand the charm of grainy crayonish vibe, but to use it in black and white manga without screentones is quite questionable move. Usually when a manga not using screentones they'll play more on the value, using contrast on black and white. But here the grainy pen make it all kinda blur. The end result is they all just looks sketchy, like someone turning in early draft rather than finished manuscript.
Also the mangaka not even using the crayonish vibe on the character cover illustration???? Thats so wasted!!!