"Seishun Butayarou wa Yumemiru Shoujo no Yume wo Minai" (rascal does not dream of dreaming girl) by Kamoshida Hajime. This is volume 6 of the series, also probably the best and worst place to stop.
This is the best place to stop in that closure to many of the loose ends can be found in this volume. It opens with what's almost a standoff between Shouko and Mai, and ends with Sakuta having to make a very difficult choice between Shouko and Mai. The chapters in between explained many things including Shouko's inexplicable age difference and Sakuta's ominous chest wounds. If you are curious about what happened just after the anime series ended, this volume has the climax to top them all.
This is also the worst place to stop, in that what follows all revelation comes what is best described as a Bad End. Every volume ends with a shocker and this volume is the worst of them all.
It's a bad end but it's not game over yet. Thankfully the story does continue, I can only optimistically hope that the author has a good plan to fix this damage.
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