If you loved Kuroko's Basketball the Movie: Last Game, try Slam Dunk 3: Crisis of Shohoku School
A bridge between a film you've already seen and one most people haven't. Slam Dunk 3: Crisis of Shohoku School has roughly 6.7× fewer votes than Kuroko's Basketball the Movie: Last Game — it's a deeper cut, not a mainstream recommendation. Here's what they share, and what the second one does that the first one doesn't.

Kuroko's Basketball the Movie: Last Game

Slam Dunk 3: Crisis of Shohoku School
What they share
Theyboth carry the playful mood tag, and they sit in Animation / Comedy territory. If that's the register that drew you to Kuroko's Basketball the Movie: Last Game, the second film will land in a comparable space — through a different lens.
What Slam Dunk 3: Crisis of Shohoku School is
The third outing finds Shohoku nursing post-Kainan wounds and a freshly cropped Sakuragi. An exhibition against the mysteriously stacked Ryoukufu is supposed to rebuild morale. In reality, it just raises the odds they’ll get dunked on again.