Whenever you read about people doing things you yourself would never dream of doing, you naturally wonder: Is it a warped individual nature that is to blame? Is it the nature of the time, the place, the circumstances?

Warped or not, an individual need never be alone. There’s always company to be found. The internet is an inexhaustible source of encounters among like-minded people who, pre-net, would almost certainly have rotted in solitary frustration.

The net’s power to bring people together is much celebrated and does much good. Its tendency to nurture our basest impulses is much derided and does much harm. There’s a site for every taste, some of them not too savory.

The rape of a wife by her husband may, depending on how you define rape, be as old as marriage. Josei Seven magazine finds it increasing — as is, it says, a purely modern twist: the posting on the net of videos to feed the husband’s pride and the wife’s actual (if she knows) or potential (if she doesn’t) mortification.

Modern pharmacology makes it easy, and the net puts modern pharmacology within easy reach of anyone.

“I slipped 30 grams of the magic drug in her wine. I took off her pajamas. She didn’t know a thing.” That’s one of the boasts Josei Seven finds posted on a site devoted to that kind of thing.

“Incidents in which wives are rendered unconscious by (drugged) drinks offered to them by their partners, including husbands, have been increasing over the past several years,” notes Mieko Kondo, a board member of a nationwide chain of shelters for victims of domestic violence.

Why?

Peer approval is surely one spur. Some videos get 1,000 and more comments. Malice, the exercise of power, the triumphant reveling in another’s pain, even if — or especially because — the other is your wife, are other motives. Another possibility emerges in an interview the Asahi Shimbun published in March with mental health care specialist Akiyoshi Saito. Saito was speaking specifically of chikan — groping in public places, commuter trains most notoriously — but his comments might apply to wife-rape as well. What begins as a thrill, Saito said, develops into an addiction. Once you start you can’t stop. The perpetrators are ill and must be treated, in his view.

Josei Seven introduces a 41-year-old woman who, marrying in 2011, was shocked to discover what her husband expected — demanded — of her sexually. She might be tired, or under the weather, or having her period — it doesn’t matter. His stock answer to any resistance she dares mount: “I work every day, I bring home the money — the least you can do is satisfy me physically.”

She’s at the end of her tether. There are no children, so divorce is a theoretical possibility — but he has videos, he tells her, which the world will enjoy watching if she doesn’t behave herself.

The law offers one recourse — again, theoretical. In 2007, a Japanese court for the first time found a man guilty of raping his wife, setting a precedent. But the course is long, the hurdles many, the psychological price high and the outcome doubtful. The legal formalities are traumatic even when the rapist is a stranger. All the more so when he is your husband.

How common is this? A Cabinet Office survey earlier this year of 1,807 women found 13.8 percent claiming to have “often” suffered violence from husbands; 17.5 percent said they had “once or twice.”

It’s an appalling statistic, damning one-third of marriages in this most peaceful of societies as violent. Kondo counsels determination, action and a refusal to be overwhelmed. She stresses the good news: The law drags its feet but shifts slowly in women’s favor; shelters do exist. And Saito’s view of sexual harassment as a male psychological disorder may, as it gains ground, at least check the harasser’s triumphant swagger.

Marriage, once the gateway to normal, stable adult life, appears increasingly suspect. Economic, social and psychological factors call its inevitability and even its desirability into question. Solitude is an increasingly acceptable alternative. Its extreme face is hikikomori — people withdrawing from society because of its harsh or ugly or uncongenial aspects and growing old alone, indifferent to and forgotten by the great world outside. As a mass phenomenon it’s scarcely thinkable without the social potentials of the internet and, in fact, it waxed with it, beginning some 25 years ago.

Shukan Josei magazine examines some “cases.” One is a 43-year-old woman who lives with her father but rarely sees him — same house, different worlds. If he thinks she’s vegetating alone in her room he’s only partly right, maybe not right at all. She shops online, plays games online and lives a life quite inconceivable a generation ago, active in its own way and yet safe, insulated. No employer will exploit her, no husband will rape her.

Such is the grim face that “reality” presents to some, a ceaseless goad to the flight hormones. What world to flee into? It depends on what you’re fleeing, also on what you’re seeking.

“Kyoko,” now 30, landed as a young woman fleeing boredom into fuzoku, the erotic entertainment industry. Her story appears in Spa! magazine. Her particular corner of this labyrinthine little kingdom consisted of “image clubs” specializing in sexual “mania” — sado-masochist playacting and so on. She enjoyed it but her club closed down and she drifted into conventional employment, an office job with a medical equipment maker. Her boss, 15 years older and rather a nice fellow, proposed. She accepted, consummating, as she thought, her re-entry into “reality.”

But fate had other plans. Her husband soon began suffering erectile dysfunction. Kyoko was sympathetic but also, after all, human. Should she go back to fuzoku? Why not? Well, there was her husband. What would he say? “I told him everything.” He hadn’t known of her past. It gave him a turn. He thought it over. Weighing his options, he found them limited. OK, he said at last.

It saved the marriage. “He’s a good guy,” says Kyoko, “really, a pleasure to be with.” From him she gets sympathetic companionship and good conversation. From fuzoku she gets what he can’t give her. Maybe one day that will change. “I still want to have his child,” she says.

Michael Hoffman is the author of “In the Land of the Kami: A Journey into the Hearts of Japan” and “Other Worlds.”