If you humor some aspects and forgo some minor inconsistencies, you'll most likely enjoy this manga.
The art is top notch. Great when serious, adorable and funny when not.
The idea is interesting, way more than the title suggests. This mangaka is more than competent when throwing twists or developing characters.
However, they've invested so much of the story into developing interest in the female protagonist. A lovable character, with a seemingly dark background. The writer had laid out several hooks and cliff hangers early on in the story and even more intense ones near the end. Not one was used. So what potentially could've been the
biggest arc in the manga, was strangely abandoned in the last few chapters. As if nothing ever happened.
This manga is a real page turner. It's been entertaining from beginning to... well, near the end. The ending was so unsatisfying, that I had to reconsider this manga as a whole. The mystery was not only left unsolved, it was ignored.
I would give this manga an 8/10 all the way to the ~200th chapter. I'd give the last ~10 chapters a 3/10. And that's being generous.
Definitely avoid it if you're in it for the ending.