Maverick Mendez Rosales, 24, was ordered held on $300,000 bail. He is also charged with extortion and misdemeanor sexual battery.
Deputy District Attorney Martin Doyle told reporters that Rosales used online sources such as Facebook and Craigslist to solicit the women.
Two victims are named in a criminal complaint against Rosales, and Doyle said authorities believe there may be more.
Rosales allegedly victimized one woman for two years, the prosecutor said.
In an interview outside the courtroom, Doyle made a plea to women who may have been victimized by Rosales.
“We certainly hope that any additional victims of Mr. Rosales come forward,'' the prosecutor said. “We're committed to holding him accountable for what he did to each of you, and we hope that you have the courage to call the District Attorney's Office and let us know what happened to you as well.''
Rosales was arrested Wednesday in Mission Valley. He faces 13 years in prison if convicted, Doyle said.
A readiness conference was set for Aug. 11 and a preliminary hearing for Aug. 13.