anonymous author; pseudonymous author; writer who conceals their identity
Refers to an author who publishes under a pen name or keeps their real identity hidden, often for privacy or artistic reasons.
That anonymous author published a bestseller without revealing their real name.
覆面作家の正体について、さまざまな憶測が飛び交っている。
Various speculations are flying around about the true identity of the pseudonymous writer.