The case is the latest dispute involving religion to come before the conservative-led court. The justices have repeatedly endorsed claims of religious discrimination in recent years.

The Montgomery County public schools, in suburban Washington, D.C., introduced the storybooks as part of an effort to better reflect the district’s diverse population.

Parents sued after the school system stopped allowing them to pull their kids from lessons that included the books. The parents argue that public schools cannot force kids to participate in instruction that violates their faith, and they pointed to the opt-out provisions in sex education classes.

The schools said allowing children to opt out of the lessons had become disruptive. Lower courts backed the schools, prompting the parents’ appeal to the Supreme Court.

Five books are at issue in the high court case, touching on the same themes found in classic stories that include Snow White, Cinderella and Peter Pan, the school system’s lawyers wrote.

In “Prince and Knight,” two men fall in love after they rescue the kingdom, and each other. In “Uncle Bobby’s Wedding,” a niece worries that her uncle will not have as much time for her after he gets married. His partner is a man.

“Love, Violet” deals with a girl’s anxiety about giving a valentine to another girl. “Born Ready” is the story of a transgender boy’s decision to share his gender identity with his family and the world. “Intersection Allies” describes nine characters of varying backgrounds, including one who is gender-fluid.

Billy Moges, a board member of the Kids First parents’ group that sued over the books, said the content is sexual, confusing and inappropriate for young schoolchildren.

The writers’ group Pen America said in a court filing what the parents want is “a constitutionally suspect book ban by another name.” Pen America reported more than 10,000 books were banned in the last school year.

A decision in Mahmoud v. Taylor is expected by early summer.