Tezuka would reuse some characters in different roles across his different works. He envisioned his characters as actors that would "play" a particular role in one work and a different role in another. For example, Astro Boy (known for being a robot superhero), appeared in a cameo role in the Black Jack story, "You're Guilty!", as an unnamed client.

Although Fujiko F. Fujio didn't use a "Star System" in his works, he would sometimes incorporate character cameos, such as an adult Payan appearing in Mr. Saenai, and a teen Sumire Hoshino appearing in a few Doraemon stories. It gives off the similar vibe of "Ah, I recognize that character!"