Piper from Zenless Zone Zero (ZZZ) is generally considered to be a petite adult likely in her mid to late twenties, possibly early thirties. She is old enough to have a commercial driver's license (CDL), which in the U.S. typically requires being at least 21 years old, indicating she is definitely an adult

. Some dialogue in the game suggests she is older than many other characters, and she herself acknowledges looking younger than she actually is

. There is some fan speculation and mixed interpretations about her exact age, with estimates ranging from mid-twenties to early thirties, but no official exact age has been confirmed. Some fans have even speculated she might be older, around 43, but this is less supported by the lore and more by fan interpretation

. In summary, Piper is most plausibly in her mid to late twenties or early thirties, appearing younger than her actual age and definitely an adult with a CDL