On the face of it, the story of Dakari Johnson — a 22-year-old backup center for the Oklahoma City Thunder — is familiar. He’s an anonymous rookie, fighting for minutes, hoping to plant the roots of a long career. When his chances have come, he has seized them.

With center Steven Adams out with a contusion to his right calf on Nov. 10, Johnson got his first N.B.A. start. Late in the game, against the Los Angeles Clippers, Johnson made a crucial jump shot, then took the opportunity to blow kisses to the sky. “His swag,” the Thunder star Paul George said after the game, “is at an all-time high.”

But since then, with Adams mostly healthy, Johnson has racked up as many D.N.P.s as meaningful minutes. From his seat on the bench, then, he seemingly represents potential yet unfulfilled. But it’s not that straightforward. Johnson comes from a long, boisterous line of activist-minded Brooklyn-bred ballers with nicknames like Slomotion. Behind that little-known rookie bench player is a true family saga — and the fulfilled dreams of generations.

“A lot of my past teammates have people in their family who play,” Johnson said. “But my family, it’s high school, pro-am, college, uncles, aunts, cousins, daughters. Everything revolves around basketball.”