One mall in the area, Sino Centre, is a popular destination for toy enthusiasts - it's full of shops selling cool figures and other items. (To get there, you can take Exit E from Mong Kok MTR station, and then walk along Nathan Road towards Yau Ma Tei.)
Yet as toy collecting grows ever more popular, fans are starting to flock to a new "hangout".
Toys' Somethin' is a five-minute walk from Sino, along Nathan Road. Dozens of students, dressed in school uniforms, are regularly seen there shopping for toys.
"I come here to check out Gundam models," says a student from TWGHs Wong Fut Nam College, who prefers to give his name only as "Leung".
"I like looking at old Gundam models, as well as the latest ones. There used to be lots of stuff we could not afford when we were little. So I come here to look for good bargains."
Manager Lap Fung, who runs a few Japanese-themed toy stores on the second floor of the building, says many youngsters visit his shops to buy Kamen Riders figures.
"The most popular ones are those from the Black RX and Shadow Moons series," says Fung, whose shop windows display a variety of toys imported from Japan, including Gundam models, Godzilla figures, and robots from anime classics such as Mado King Granzort and Mashin Hero Wataru.
One floor below, Zoe Lee runs Funhouse, a shop selling everything to do with Lego - from a single, tiny brick unit to an epic replica of Australia's Sydney Opera House.
"The little Lego Iron Man is the hottest item for teenagers now," she says. "The Lego Volkswagen Type 2 camper van is also very popular because of its lovely inner compartment. You can actually see the bed and sofa inside."
However, none of these hot items is as interesting as seeing how the mall has evolved in the past decade.
Lee says there were few toy shops when she opened eight years ago.
And Fung says the mall is now a hub for young toy enthusiasts.
"They share their passion for anime and manga with one another when they come here," he says. "But the interesting thing is, I hear that once they leave this building, they don't seem to talk about it any longer."
He says that interest in the type of toys he sells is thriving, despite fears that the rapid growth in computers games and other new technology would lead to scale-model toys with moveable arms and legs becoming obsolete.
"There are quite a few youngsters who like playing with 'physical toys' that they can actually get their hands on," Fung says.
"More and more young Hongkongers are taking an interest in the Japanese manga culture these days."
Fung says the most popular items he sells are figures and other toy items linked to the characters from the latest anime series, rather than those based on classic shows or manga.
"Youngsters will watch the shows on television and come here to buy the figures afterwards," he says.
"Toys from older cartoon shows, such as robots from Matchless Raijin-Oh [first shown on television in 1991] are less known to young people these days."
Lee agrees that demand is greatest for new products. "Young people love the Lego Super Heroes - Spider-Man, Superman, Batman, X-Men and Iron Man - most of all," she says.
As the popularity of manga and Marvel doesn't seem to be diminishing any time soon, it seems that any guys who collect these toys on the sly can reveal their secret - toy collecting - is its own sort of cool.