The American anime convention, Otakon (“Otaku Convention”), begins with a costume parade before it officially opens. Last week I had a bird’s-eye view of the spectacle from my 14th-floor hotel room in Baltimore, Maryland. An endless army of imaginary characters trudged across the elevated concourse and down adjacent sidewalks to the Baltimore Convention Center to register and obtain entry badges. Most were instantly recognizable from anime series old and new, brandishing swords or other weaponry fashioned out of homemade materials, or wearing massive multicolored wigs, capes or sewn-on tails — or very little at all.

For three days the colorful mob overtook Baltimore’s downtown and Inner Harbor neighborhoods, and until they returned to their hometowns in 42 different states, you couldn’t walk 20 meters without bumping into, overhearing and/or following them.

Roughly 35,000 fans of Japanese pop culture attended the event, according to Otakon’s director of press and publicity, Victor Albisharat. They skewed 53 percent female; 75 percent aged 19-34, and organizers say they keep getting younger.

“People go to Otakon for different things,” says Lance Heiskell, director of corporate strategy for Funimation Entertainment, one of the largest distributors of anime in the United States. “This year they had (Japanese anime soundtrack composer) Yoko Kanno. Some people came for the J-Pop of T.M. Revolution. Others just want to dress up and get together. And some people just come to dance at the nightly raves because, you know, they’re safe.”

This year also saw the celebration of Otakon’s 20th anniversary, a milestone for any kind of convention, let alone one devoted to a popular culture in a foreign language from a country thousands of miles away. Otakon retains a special place among fans and industry guests from both sides of the Pacific, artists, performers, panelists — and even its own mostly volunteer staff.

Otakon’s nonprofit status and its slogan — “by fans, for fans” — is a rarity in an entertainment convention business that often relies upon sponsorship deals and top-down decision-making. Nearly 850 volunteers staffed Otakon 2013.

“We’re a grass-roots-driven organization,” says Otakon Chair Terry Chu. “We have a different approach to things, a different template. The model is a family, not just figuratively, but literally. We now have volunteers who are the children of volunteers who met at the convention and got married.”

You hear the word “family” a lot when people talk about Otakon’s 20-year legacy. “We don’t make distinctions between the staff, the fans and the guests,” adds Jim Vowles, Otakon’s director of guest relations. “We try to treat all three with the same level of respect. I think that’s the difference (between us and others).”

Nonetheless, there have been some hiccups. A train accident in 2001 released chemicals that triggered pressures beneath the city’s streets, blowing open several manhole covers around the convention center. In 2010, the center’s fire alarms sounded by mistake, causing the evacuation of over 20,000 attendees during peak hours. Both events were handled with grace, and the convention has had no incidents of serious crime or assault.

“(During) the fire-alarm evacuation,” says Vowles, “our volunteer staff were praised by the professionals who were supposed to take care of it. The fans and guests evacuated calmly and things got back on track. We were very proud of them.”

Around 260 anime conventions take place in North America annually. “I don’t know what it is (about Otakon),” says Heiskell. “But everyone is cool and collected on staff here. It’s not cliqueish, and that makes everything move with well-oiled efficiency. I’ve been attending this con for 10 years, and I always say to people, ‘If I ever leave the anime industry, I want to join (the Otakon) staff.’

“The (type of) fans helps, too,” he adds. “Maybe anime fans are the softer, gentler geek. You have to have the cognitive reasoning to understand and appreciate most of these shows. We tend to try to get along.”

Convention highlights last weekend included a screening of anime maestro Mamoru Hosoda’s “Wolf Children,” dubbed in English by voice actors who were on hand to discuss their work, and a solo performance by revered pianist/composer Yoko Kanno.

Hosoda, a Ghibli alumnus, is a patient, literate auteur. His films do not feature giant robots, Naruto-like ninjas or Sailor Moon-esque pixies. Kanno is an accomplished jazz and classical pianist and composer. How would these American kids, exhibitionistic cosplayers and proud nerds react to art slightly more highbrow than “One Piece” and “Escaflowne”?

They didn’t just react; they engaged. At both events, Otakon fans were silent, quietly sobbing amid a scene, or singing in unison to a Kanno soundtrack. The Hosoda screening was sold out; no one left early, and amid a slowly unraveling tragedy, no one seemed restless. Kanno’s solo performance, also sold out, combined nightclub-styled blues and jazz riffs with an animated set that transformed her piano into a cat and a screen for quivering hearts.

“There’s a special atmosphere (at Otakon) that is about the vibrancy of the community,” says Christopher Macdonald, publisher of Anime News Network, the largest English-language portal for news about the anime industry. “People here can be themselves. Even the structure of the venue, with lots of outdoor space that is protected and safe, gives cosplayers a chance to pose and take photos without fear. It’s crowd-sourced fun.”

Of course, with fandom at the forefront, being a guest at an anime convention is a bit like being a performer on a cruise ship: Most are happy you’re there, and some will actually seek you out, but their first priority is to have a good time.

At the closing dinner, a private affair after the event had officially ended, staffers were thanked, guests were honored and glasses were raised. Though I had only been there for four days (landing one day early to prep before the chaos), I did feel like part of the community — a minor cast member, at least, who managed to play his role in a short scene of an epic drama.

Fittingly, the final announcement signaled a big step forward — to 2017, when Otakon will move into bigger, more modern venues in nearby Washington, D.C. And the closing toast was to Matt Pyson — the only Otakon volunteer who had served on staff for each and every one of its 20 years, from 1993.

“Cheers!” rose the voices, and before the glasses clinked, “Kampai!”

Roland Kelts is the author of “Japanamerica: How Japanese Pop Culture has Invaded the U.S.” He is a visiting scholar at Keio University in Tokyo.