When I arrived at the Tokyo Metropolitan Museum of Photography the other Sunday, I thought it was early enough to avoid the crowds. But a long queue had already formed at the entrance to the particular exhibition hall I was heading for. Thirty minutes of waiting later, I was guided to another long queue - to gain access to the otaku section.
The term otaku refers to Japan's unique subculture, and the crowds had gathered for the homecoming of an otaku show, which wowed art lovers at the International Architecture Exhibition during the Venice Biennale last autumn.
Inside the exhibition, I found a makeshift market featuring a variety of manga and anime - Japanese comics and the film version of the same - as well as posters and computer-game graphics. There were also tiny monsters and dolls, gifts of sweets and chewing gum, as well as hi-tech toys and artefacts.
The display area, with hundreds of colourful posters hanging from the ceiling, featured hundreds of glass display cases where individuals had displayed their collections, and a model of Akihabara (the area of Tokyo which sells everything electrical - and has now become the otaku capital).
Previously, the term meant 'you' in conversational Japanese. Over time, it came to mean 'manic fans'. Most recently, it refers to real obsessives, usually male, who are preoccupied with manga, videos and games. They tend to focus on their own subculture, shunning mass-market anime films or commercially successful characters.
Their antisocial lives revolve around their illusory world, and their collections and hobbies, with some even taking part in 'plays' (where they masquerade as their favourite character). Many Japanese only learned of the term through the media, when people who fit the category committed gruesome crimes.
But the organisers of the five-week exhibition, which ended last Sunday, were trying to present a different perspective by showing the complete otaku 'character', their visions, values and perceptions. Such a person can shape cities and space in alternative ways, they say.
Whatever the theory, 18,000 people visited the show. On the last day, 1,700 fans attended, six times the number of people the museum would expect during this quiet season. In search of what otaku is really all about, I asked some for their views. Young girls say its fans are weird; parents think they are incomprehensible; art critics call them creative and psychiatrists label them extreme introverts.
This power is subtly shaping Japan, and possibly the rest of the world, too - without most of us knowing.