Literally the best manga that Adachi has ever pumped out, even when you may see Touch and Cross Game can be listed as no less than excellent. This manga has every thing that you can get from a typical Adachi manga but on steroid: actual exhilarating baseball matches, crazy dynamic but also super unbalanced relationships, struggles with actual effort given, best best best middle friend ever, really competent sidekicks and not to forget the maximum overdrive Adachi's baiting power. Try counting the number of encounters that Hiiro and Hikari got together while Hideo seemed to be cucked a bunch of times. That's Adachi's power at its peak.
The ending was straighter set than you would think. Try putting your mind in more crucial dialogues while binge reading the manga, as when you think you can get something out of every character's actions it's much more fun to read. Adachi already set up all the painfully obvious clues for you to even solve romantic cases when he was baiting you all along, to the point you instantly learnt how this manga would end and why it ended like this after finishing reading the second last chapter. The final chapter is to be honest unnecessary and its purpose is just to have a bit of aftertaste for the manga so that you cannot really complain. And yes, I adore this ending just to spite readers who only read on the surface and never dig in between the lines.
Or if you do not get how this manga is legendary then you can read other released manga by this guy to get the gist of Adachi's plot style. Some day you may get it hopefully. And Mix may also be as good as this, hopefully (never; you also understand why).