Why is the anime's final game not in the manga?

The last game in the Slam Dunk anime, Shohoku against a combined team drawn from Shoyo and Ryonan, appears nowhere in Inoue's manga. It was created for television, filling the final episodes with a match that could feel like a climax without touching the national tournament the manga was still building toward.

The production logic is visible in the dates. The anime ended March 23, 1996; the manga ended June 17, 1996. The show had caught up with its source and its broadcast run ended before the Inter High could be adapted, so the staff closed with fan service of a thoughtful kind: one more look at Fujima, Sendoh and the rival schools, a 76 to 74 Shohoku win, and a promise on a train platform.

Readers meeting the franchise through the manga often assume the game must be a chapter they skipped. It is instead a small piece of authorized apocrypha, and the only animated version of Shohoku's complete starting five playing a full game together until 2022.