Japan is the only country among the world’s wealthiest democracies that has not legalized same-sex unions. Few celebrities are openly gay. Conservative groups oppose legislative efforts to protect the L.G.B.T.Q. community.

But now, Netflix is introducing the country’s first same-sex dating reality series.

Over 10 episodes of “The Boyfriend,” which will be available in 190 countries beginning on July 9, a group of nine men gather in a luxury beach house outside Tokyo. The format evokes Japan’s most popular romantic reality show, “Terrace House,” with its assembly of clean cut and exceedingly polite cast members, overseen by a panel of jovial commentators.

The vibe is wholesome and mostly chaste. The men, who range in age from 22 to 36, operate a coffee truck during the day and cook dinner at night, with occasional forays outside for dates. One of the biggest (among very few) conflicts of the series revolves around the cost of buying raw chicken to make protein shakes for a club dancer who is trying to maintain his physique. Sex rarely comes up, and friendship and self-improvement feature as prominently as romance.

In Japan, the handful of openly gay and transgender performers who regularly appear on television are typically flamboyant, effeminate comic foils who are shoehorned into exaggerated stereotypes. With “The Boyfriend,” Dai Ota, the executive producer, said he wanted to “portray same-sex relationships as they really are.”

Mr. Ota, who was also a producer of “Terrace House,” which was made by Fuji TV and licensed and distributed globally by Netflix, said he had avoided “the approach of ‘let’s include people who cause problems.’”

“The Boyfriend,” he said, represents diversity in another way — with cast members of South Korean, Taiwanese and multiethnic heritages.

Despite how Japan lags in L.G.B.T.Q. rights, Mr. Ota said the show is not meant to offer overt political or social commentary. Cast members were not advised against speaking about the social challenges of being gay or bisexual in Japan, he said, but during the audition process, he reminded prospective participants that “ultimately it will be streamed, and a wide range of viewers will be able to hear those thoughts.”

Soshi Matsuoka, the founder of Fair, an L.G.B.T.Q. advocacy group in Tokyo who has watched the series, said its mere existence “shows a change in the society.” But he said he wished the cast talked more openly about their sexuality and the social context of the L.G.B.T.Q. community in Japan.

While “The Boyfriend” may be the first same-sex reality dating show set in Japan, there are a growing number of queer dating shows, including “The Ultimatum: Queer Love,” also for Netflix; “I Kissed a Boy” and “I Kissed a Girl” on the BBC; “For the Love of DILFS,” available on Apple TV+, and “His Man” in South Korea.

Taiki Takahashi, a gay model and social media influencer who served as casting director on “The Boyfriend,” said he had “a lot of expectation and hope” for the show.

“I won’t say we can change society,” he said in an interview at Netflix’s offices in Tokyo. “But I do want many people to feel some kind of impact.”

About 50 men auditioned after Mr. Takahashi put out casting calls on social media and recruited from his own networks. He said he deliberately chose “people who would be loved” and that he avoided men who “feel the pressure of ‘I have to become a certain character because I am going to be on TV,’ or ‘since I am gay I have to act gay.’”

The shadow of “Terrace House” inevitably hangs over “The Boyfriend.” They share the same basic format and one of the commentators — Yoshimi Tokui — has returned to the studio where he and a slate of television personalities dissect the interactions between the men on the show.

At the end of the fifth season of “Terrace House,” which became a global hit, one of the cast members, Hana Kimura, a professional wrestler in Japan, took her own life. She left several suicide notes and had posted ominous notes on Twitter and Instagram before she died.

Her mother, Kyoko Kimura, has filed a lawsuit against Fuji TV and two other production companies, accusing them of failing to protect her daughter from slanderous comments and forcing her to behave on the show in a way that attracted mass criticism online. Ms. Kimura is seeking close to $1 million in damages.

Mr. Ota said Netflix has enlisted mental health professionals to consult with the cast and “to create a production environment where no one gets hurt.” He said Netflix had performed background checks on each of the cast members and that after the show airs, “we will take care of them if they have even the slightest bit of anxiety.” Netflix did not make any of the cast members available for an interview.

Although polls show that more than 70 percent of the Japanese public supports legalizing same-sex unions, gay and transgender people are still subject to discrimination and hate speech.

Ms. Kimura, 47, said in a video interview that she knew from her daughter’s experience that young people new to international exposure “can’t imagine what it would be like to actually receive hundreds or thousands of slanderous comments from all over the world a day.”

“The reality TV format itself is dangerous,” she said. “And especially in Japan, where few people have a detailed understanding of the existence of L.G.B.T.Q. people.”

Durian Lollobrigida, a drag queen who is one of the five commentators on “The Boyfriend,” said he wanted to join the show to help “protect” the cast members.

“I thought it wouldn’t be good if heterosexual people who are in the majority were just watching gay men mingle,” Mr. Lollobrigida, 39, said. “So I thought it was necessary for someone to be there to act as a translator.”

Once filming started, he said, he grew comfortable with his fellow commentators and realized “I didn’t have to worry about these things.”

Even without explicit political advocacy, the show could have a subtle effect on social attitudes, Mr. Lollobrigida said. “In order to get various L.G.B.T.Q.+ rights, of course raising our voices and protesting is important,” he said. “But at the same time, I think it is important to normalize it through entertainment.”

Whether the show lays the groundwork for eventual political change is questionable, said Jennifer Robertson, a professor emerita of anthropology at the University of Michigan who has written frequently about L.G.B.T.Q. culture in Japan.

She acknowledged that the sweet, low-drama cast members could make for heartwarming viewing. In many ways, they offer an idealized contrast to “heteronormative couples who are squabbling about kitchen cleanup and kids,” Ms. Robertson said. Indeed, several of them — not just the professional chef in the cast — appear to be talented home cooks, and they all work to keep the house clean, qualities not typically associated with most men in Japan.

But if the goal was to encourage less tolerant Japanese viewers to become more accepting of gay and bisexual men, Ms. Robertson added, she wondered whether such people were likely to watch a show like “The Boyfriend” anyway.

“Cutesification in a show to garner support among people who are probably already supporting L.G.B.T.Q. is not going to be a push in any direction toward political ratification of gay marriage,” she said.