So close to being perfect in my opinion. The plot is interesting and overarching, while remaining tight and tantalisingly just out of grasp. The artwork is some of the cleanest I've ever seen! Humour is interspersed alongside actual worldly knowledge and academic theory, which, while can take you out of the moment when a character suddenly starts theorising academia alongside an enemy, I found informative and enjoyable and part of the fun being that the mangaka and their editor are made characters in the story and interact with the main cast often. Even saving their lives.
But, some characters still felt like they are there to fulfil a purpose, and as such are more agents of advancing the plot rather than believable people. Maya (for example) starts off as a badass fem-fatale and undercover spy, but quickly devolves into a "damsel in distress", even going so far as cooking and cleaning for the "bad guys". This is after the male lead has sex with her, of course. Maya then goes from constant captive to being "fridged" in order to motivate our hero, Mikado, into his final form.
Males in this are almost always some variant of the "crouching moron, hidden badass" trope, with the hidden bad-ass usually some alpha male power fantasy, from modern samurai to literally turning men (and like three women) into animals (sort of). So not huge on sex equality, although it does have moments.
Why isn't this a 10? Aside from everything I've mentioned (both good and bad), right at the penultimate moment, there's a time skip to Tokyo from the Jungles of South America. It serves no purpose. The very next thing the protagonists do is grab the "bad guy" and take him back to South America to face Mikado in the fight they would have had before the time skip any way.