Like a lot of 20-year-olds, Kae Takahashi has a page on U.S.-based MySpace, and there is no mistaking it for anyone else's.
It's got pictures of the funky Tokyoite modeling the clothes she designs in her spare time, along with her name, plus personal details and ramblings in slightly awkward English about her love life.
Switch to her site on mixi, Japan's dominant online hangout, and her identity vanishes.
There, Takahashi uses a fake name and says she is an 88-year-old from the town of "Christmas." Her profile is locked to outsiders.
Takahashi is far from alone: the vast majority of mixi's roughly 15 million users don't reveal anything about themselves.
It's not just mixi. It's Japan.
YouTube is wildly successful here, but rare is the user who follows the site's enticement to "Broadcast Yourself." Posting pet videos is far more popular, and has bred a generation of animal celebrities.
On large matchmaking sites like Match.com the whole point is to open up and meet strangers. But fewer than half of Match's paying members in Japan are willing to post their photos, compared with nearly all members in the U.S.
Welcome to Japan's online social scene, where you're unlikely to meet anyone you don't know already. The early promises of a new, open social frontier, akin to the identity-centric world of Facebook and MySpace in the U.S., have been replaced by a realm where people stay safely within their circles of friends and few reveal themselves to strangers.
"There is the sense that, `My face just isn't that interesting, or I'm not attractive — there is nothing special about me to show people,'" says Tetsuya Shibui, a writer who has long followed the Internet in Japan.
Indeed, the Japanese virtual world has turned out just like the real one.
People rarely give their first names to those they don't know well. Spontaneous exchanges are uncommon even on the tightly packed trains and streets of Tokyo. TV news shows often blur the faces of those caught in background footage and photos to protect their privacy.
Takahashi, who joined mixi three years ago, keeps her profile hidden so that only users she specifically invites can see it. That list of online friends has expanded to nearly 300 people, only a few of whom she didn't first meet in person, but she has removed personal details and scaled down past postings.
"If I say too much, the wrong people will read it — it could get ugly," she says.
The penchant for invisibility has made it hard for Western social networks to establish themselves. Belated forays into the Japanese market by Facebook Inc. and News Corp.'s MySpace, for instance, have failed to generate much of a buzz.
Google Inc., which operates YouTube, has tried to convince the Japanese to loosen up, running events in Tokyo in which girls in miniskirts roam the streets with giant picture frames and video cameras, soliciting pedestrians to frame themselves and record a clip for the site.
But it has since eased back on such efforts. YouTube's latest campaign in Japan involves people uploading pictures of their pets.
"We can't change the mindset of Japanese people," says Tomoe Makino, in charge of partner development at YouTube's Japan site. "It's the uniqueness of Japanese culture — anonymous works in Japan."
It wasn't always like that. When mixi was launched in early 2004, many people registered with their own names and photos.
"It was all friends, or friends-of-friends, so you could easily search using real names, and it was easy to be found," Shibui says.
But mixi quickly grew in popularity, and was heavily featured in the media as it sped toward a public stock offering in 2006. New members can join only with invitations from existing users, but some people began to send out invites randomly. The circle-of-friends concept was broken, and existing users began to lock their profiles and withdraw behind anonymous user names.
Naoko Ito is a typical denizen of Japan's online scene.
The office worker's video clips of her cats running amok at her house are among the most popular on YouTube Japan. Her blog features daily pictures of the feline antics and is popular enough to have spawned a book deal. But she doesn't post her name and in five years of uploading images has only rarely shown her face.
She says Japanese are just not used to putting themselves in the spotlight, and in the rare cases she has uploaded her picture it has been to show she is like everyone else.
"I want people to feel that I'm a very normal person, nothing special, just someone who likes cats," she wrote in an e-mail.
The reluctance to reveal oneself online is coupled with a general distrust of those who do, and foreign sites like Match.com have had to adjust. The site has had a local office since 2004, and has added Japan-only features like identity certification to generate an atmosphere of trust.
"When we did research on Japanese consumers, we found that the No. 1 reason for not using online dating is that they don't know if people are real or not," says Match.com's Japan president, Katsu Kuwano.
Match has increased its paying users in Japan by tailoring its approach to better fit marriage-minded Japanese women, timing advertising campaigns with national holidays when they travel home and face pressure from parents to find a mate.
But Kuwano says even among the women hunting for a spouse on the site, only 40 percent are willing to post a picture of themselves, and men are far less likely to respond without getting a glimpse first.
The company hopes to make more people show themselves online by defining itself in a less Web-centric way, latching on to the broader "konkatsu" movement in Japan, in which people actively seek out marriage partners. Match has also held offline events at Tokyo restaurants.
Even if the Japanese Internet isn't a place to meet new people, the fixation with anonymity still has led to an explosion in self-expression — a sea change in a culture where strong opinions are usually kept to oneself. Anonymous Japanese bulletin boards like the massive 2channel are highly popular, with active forums popping up to discuss news events just minutes after they occur.
As is true elsewhere in the world, Japan's online anonymity can bring out the uglier side of human nature, but observers like the writer Shibui find that it is also freeing people to speak their minds.
"In using the Internet to anonymously talk about their troubles, or show off their strong points, or make people laugh," he said, "people in Japan can now interact based on what is actually being said, without worrying about who is talking."