I just finished the manga recently, and overall I found it a little lacklustre. For one thing the story feels like it could have been told in half the time. It feels like it just gets bogged down with pages and pages of pseudo cerebral kung fu, where characters are endlessly trying to anticipate everyones moves and out think each other, which for the most part doesn't come across particularly clever, it just comes across tiresome. I'm reading it like "ugh I know how clever these people are meant to be, get the fuck on with it". Pages of characters being like "L likely suspects me of doing Y, but he likely knows I suspect him, of suspecting me, so I really should do Y" while other characters are going through the same mental gymnastics is not very entertaining.
In addition, I felt they didn't really know where to take the themes and ideas. It starts quite strong, but by the end, it doesn't really have anything to say that hasn't already been said by a bunch of other stories.
That being said, I am hoping the movie leverages the basic premise, and manages to explore some new ideas with them.
