Bill and Carol Muto on their wedding day, eight years after the U.S. Supreme Court, in Loving v. Virginia, struck down interracial-marriage bans. COURTESY BILL AND CAROL MUTO

At my parents’ wedding, in Blacksburg, Virginia, my mom wore a floppy, wide-brimmed hat atop her feathered hair. My dad wore lightly flared pants and had sideburns that almost reached his jaw. Peter, Paul and Mary music played at their ceremony, and at the reception afterward they drank sherbet punch alongside friends and family members dressed in plaid and platform shoes. It was a fairly ordinary American wedding in 1975, save for one distinction: the bride was white, and the groom was Asian.

My dad, a third-generation Japanese-American from Los Angeles, and my mom, from Gettysburg, Pennsylvania, had met in Michigan, in 1970, while he was in the Air Force and she was in college studying nursing. They eventually settled in Texas, where they raised my three siblings and me. As a gay man, I’ve often thought about how my parents’ timing was fortuitous. Just a few years earlier, their marriage may not have been legal in the state where they wed, Virginia. The new film “Loving,” directed by Jeff Nichols, tells the story of the couple who changed that: Mildred and Richard Loving, a black woman and a white man who were arrested in Virginia in 1958 and sentenced to prison there after marrying in Washington, D.C. The couple, played by Ruth Negga and Joel Edgerton, toiled silently for years, unable to live openly together in their home state, until their case reached the Supreme Court—which, in a unanimous decision in 1967, struck down all interracial-marriage bans throughout the U.S.

The Lovings are the couple whose names we rightfully remember from the case, and they’re indeed the stars of the film. But, buried in the footnotes of the Lovings’ story, a little-known name caught my attention—that of a Japanese-American lawyer who gave Asian-Americans, and families like mine, a voice at a pivotal moment in constitutional history.

On April 10, 1967, that lawyer, named William Marutani, stood in front of the Supreme Court. The Lovings’ case was handled by two young volunteer A.C.L.U. lawyers, Bernard Cohen and Philip Hirschkop (played in the film by Nick Kroll and Jon Bass), who argued on behalf of the Lovings that day. But, in a rare move for the Court, the Justices had also granted speaking time to one of the outside groups that had filed an amicus brief in support of the Lovings: the Japanese American Citizens League.

Only about seventeen hundred people of Japanese descent lived in Virginia as of the 1960 U.S. Census, but the J.A.C.L., which had fought for years against interracial-marriage bans throughout the United States, wanted to show how Virginia’s law hurt even small minority groups. While Cohen and Hirschkop’s arguments in the case largely centered on legal doctrine like equal protection and due process, Marutani, who was then serving as the J.A.C.L.’s general counsel, challenged the idea of race in general and focussed on the law’s practical effect on Japanese-Americans.

Marutani opened his arguments by questioning the concept of whiteness as defined under Virginia law, which barred white residents from marrying anyone who had any “trace whatsoever of any blood other than Caucasian.” He declared that, as the American-born son of parents from Japan, he was likely one of the few people in the courtroom who could declare “with some degree of certainty the veracity of his race.” Given Europe’s history of “invasions, cross-invasions, population shifts with the inevitable cross-breeding which follows,” as well as the melting-pot nature of America, most white people in Virginia would struggle to prove their racial purity, he said. Virginia’s law, he added, left the interpretation of these racial designations up to laymen, like the county clerks who granted marriage licenses. “I believe no citation is required to state or to conclude that this is vagueness in its grossest sense,” he told the Court. Even for those who could prove their racial purity, the J.A.C.L noted in its brief, it was unclear in Virginia and in many other states that banned interracial marriage “whether or not a person of Japanese ancestry is a member of the class severally designated as ‘white person,’ ‘Caucasian’ or ‘colored person.’ ”

Marutani also took issue with the state’s justification for banning interracial marriage. Virginia had declared an interest, he said, in maintaining the “ ‘purity of public morals,’ ‘preservation of racial integrity’ as well as ‘racial pride’ and ‘to prevent a mongrel breed of citizens.’ ” But the fact that the state prohibited only white people from marrying outside their race, thus allowing all other races to intermarry, exposed the ban “for exactly what it is—it is a white-supremacy law,” he said. (In a peculiar aside, Justice Hugo Black asked Marutani whether Japan prohibited Japanese citizens from marrying white people. Marutani said he didn’t know. But, he added, “I can state, for example, that my own mother would have strenuously objected to my marrying a person of the white race.”)

During oral arguments, Chief Justice Earl Warren asked the lawyer defending Virginia’s laws, R. D. McIlwaine III, why a law concerned with racial purity wouldn’t also address other racial groups like Asians. “This Court has clearly said that a statute is not unconstitutional simply because it does not reach every facet of the evil with which it might conceivably deal,” McIlwaine responded, adding, “You cannot inflate this minority group into constitutional significance.”

Marutani’s appearance before the Court that day was brief; his arguments lasted only about fifteen minutes. He isn’t depicted in “Loving,” and his exchange with the Justices that day gets, at most, a passing mention in many historical texts. But Marutani, who died in 2004, didn’t go unnoticed for his life’s work. In the sixties, after attending law school at the University of Chicago, he served as a volunteer civil-rights lawyer in the South, and in 1975 he was appointed to the Court of Common Pleas of Philadelphia County, becoming the first Asian-American judge in Pennsylvania.

William Marutani, surrounded by family members, receives his judicial robes as a judge on the Court of Common Pleas of Philadelphia County, in June, 1975. COURTESY NANCY MARUTANI

Marutani’s daughter Nancy, a lawyer in Los Angeles, told me that he never talked much at home about his work, including his involvement in the Loving case. But she said that his strong civil-rights advocacy throughout his life probably stemmed from the injustice he faced as a young man during the Second World War, when he was incarcerated at a Japanese-internment camp called Tule Lake, in northern California. “I believe that it affected him deeply,” she said. “He was born here”—in Washington State—“and he was a good student, so I think that the civil-rights work that he did, the work that he did on Loving v. Virginia, was because he was compelled to take up the cause of protecting people who were subjected to unequal application of the law just because of their color, their race, their religion. To him, that wasn’t American.” My own family was acutely familiar with the injustice that likely guided Marutani’s life’s work: my dad’s parents met, and wed, at the same internment camp.

In 1981, President Jimmy Carter appointed Marutani to the Commission on Wartime Relocation and Internment of Civilians, which recommended that the U.S. government offer a formal apology and reparations payments to Japanese-Americans who had been interned during the Second World War. (The Civil Liberties Act of 1988, signed by President Ronald Reagan, granted twenty thousand dollars to every surviving internee.)