A bit more closure on some of the characters would've been nice. But overall, it was a satisfying ending for a great series! My only real compliant for this series is that it heavily relies on miracles and coincidences way too much. I get that Onizuka's supposed to be a miracle man, but jeez, I wouldn't be surprised if there was a plot twist at the end showing that Onizuka is a legit god. Although most of the series has the same setup of: A student/teacher hates Onizuka's ways -> wants to get rid of them from the school -> uses complex plans to try to get rid of him -> ends up backfiring -> Onizuka teases them a bit -> flashbacks for the bad guy/girl, showing why we should sympathize with them -> ends up with a change of heart and realizes that Onizuka's isn't all that bad. It's a repetitive formula that somehow keeps the series going without feeling stale and keeps it almost always entertaining. The setups given in the series automatically make you want to root for Onizuka, and that's enough for this series to become a memorable one. Combine that with the series' themes, life lessons, and social commentaries, and you got yourself an amazing series. I'm also surprised by how much I ended up liking the supporting characters. I think the final arc overdid it a bit, with Sho being the worst of the worst, yet get's little-to-no consequences for his actions. Plus we got Onizuka coming back from the dead, which was both a wtf and an lol type of moment.
Overall, completely satisfied with the manga. Probably an 8.4/10 and will definitely give Shonan Junai Gumi are read someday.