Watanabe Aya is a Japanese screenwriter from Hyogo prefecture. She graduated from Konan Women's University. After graduating from college, she spent five years in Germany. Later, she got married and lived in Shimane prefecture while running a grocery store.

In 1999, she applied for the scenario entry section "Shinonbori" (present · Ghibel Communication Playworks) for the movie by a director Shunji Iwai.

In 2003, she made the screenplay debut with "Jose, Tiger and Fish."

She lives now in Shimane prefecture with her husband and two children even after becoming a professional screenwriter.