It's a Sunday afternoon in Tokyo and Sunshine Creation is in full swing. Thousands of manga fans, mostly men, crowd into an exhibition centre, poring over manga comic magazines laid out for sale on trestle tables snaking around the rooms.
Posters of elfin-faced, doe-eyed cartoon heroines, many of them scantily clad and impossibly proportioned, turn the cavernous space into a riot of colour.
"This area is mainly dealing with sexual creations," explains Hide, one of the event organisers.
We stop at one table where the covers on display feature two topless girls. To my eyes they look to be in their early or pre-teens, and the stories show them engaged in explicit sexual acts.
Several other stands are selling similar material. It would certainly be considered controversial, and possibly illegal, in the UK, Australia or Canada, but here it's no big deal.
The Sunshine Creation show
"Everyone knows that child abuse is not a good thing," Hide says. "But having that kind of emotion is free, enjoying imagining some sexual situation with a child is not prohibited." No, but neither should it be encouraged. More than imagination is at work here, it is blatant pornography appealing to men's 'inner pedophile'! It's utterly disgraceful.
His candour takes me by surprise. He then introduces me to the word "Lolicon", short for "Lolita complex" - the name for manga featuring young girls engaged in sexually explicit scenarios. It can involve incest, rape and other taboos, though Hide's tastes lie more with high-school romance.
"I like young-girl sexual creations, Lolicon is just one hobby of my many hobbies," he says.
I ask what his wife, standing nearby, thinks of his "hobby".
"She probably thinks no problem," he replies. "Because she loves young boys sexually interacting with each other." OMG!
Material like this is a tiny part of Japan's huge manga industry, which generates around US $3.6bn in sales annually. But it attracts a lot of attention and controversy.
In June 2014, Japan's parliament voted to ban the possession of real images of child sexual abuse. Production and distribution of these images had been illegal since 1999, but Japan was the last country in the OECD to outlaw possession.
At the time there were calls to also outlaw "virtual" sexual images - in manga, anime and games - of characters who appear to be under 18. But after much debate, Japan's parliament decided against this. The decision drew condemnation from child protection campaigners and NGOs, particularly outside Japan.
One clue to understanding it is in the fact that Hide was happily discussing his "hobby" with me only minutes after we first met. Although manga involving very young children does appear to have some social stigma attached to it, sexual material involving adolescents is a fairly mainstream interest.
Japan's legislators were apparently reluctant to put large numbers of manga fans - potentially millions - on the wrong side of the law.
Fans like Hide argue they are just enjoying harmless fantasy. No child models or actors are involved, he says, so "there is no child abuse for creating sexual topic mangas".
But is the boundary between fantasy and reality always clear?
Tokyo's Akihabara district is the spiritual home of the manga world, a place where neon signs and loud pop music overwhelm the eyes and ears. Multi-storey bookshops line the streets, selling manga on every topic under the sun.
|Akihabara shop window|
"People get sexually excited by something, then become used to it," says Tomo, who works behind the counter in one of the adult stores. "So they are always looking for something new, and get sexually excited by young, immature women."
This is what worries critics - the concern that even if no-one is harmed in the creation of sexually explicit manga, it might normalise, facilitate, or lead to an increased risk of sexual abuse.
|Figurines of schoolgirls|
You don't have to look far in Japan to find a fascination with youth. Pop groups of young girls perform for crowds of adult men. And from billboards and advertisements to manga, schoolgirl imagery is everywhere.
LiLy, a popular writer of books for young women - Sex in the City, Tokyo-style, she says - told me about her school days when men would approach her and her friends and offer money for their socks or panties.
The family model of LiLy's parents' era still holds strong sway in Japan - a father who earns the money and a mother who stays at home as a housewife. But the weakness of Japan's economy has made this difficult for men to realise.
"There are people business-wise who are not successful, maybe they are running into fantasy with Lolicon manga.
"I hate it, I seriously hate it. I want Japan to kick out the kinky, just leave children out of that kinkiness, even your fantasy."
But others are sceptical about how far the government should step in to prescribe and enforce a particular vision of what's "good" or "proper", especially regarding people's fantasies.
"There's every reason to be critical, that's fine," says manga translator and free-speech advocate Dan Kanemitsu. "But when you give people the authority to police others based on what they might do or what they think, that's thought-policing." What a bunch of bull! It's not thought policing, it's visual policing. They wouldn't be restricting what you think, just what you look at. The difference is huge.
"I'm not comfortable with it, but it is not my right to tell people how they think or what they want to share," he says. "As long as it doesn't infringe upon people's human rights, what's wrong with having a fantasy life?"
Japan and images of child sexual abuse
Japan outlawed the production and distribution of images of sexual abuse of children in 1999 - 21 years after the UK
In 2013, the US State Department described Japan as an "international hub for the production and trafficking of child pornography"
Japan's police agency reported 1,644 offences in 2013 - more than in any year since the 1999 law came into force
In June 2014, Japan banned possession of real images of child sexual abuse - people were given one year to comply
Among the manga shops of Akihabara, child protection campaigner Kazuna Kanajiri takes me to see something she thinks is a much bigger problem than cartoons and comics. We climb a flight of stairs off the main street and emerge into a room packed full of DVDs.
Kazuna picks one off the shelf - it features real images of a girl she says is five years old, wearing a skimpy swimsuit and posing in sexually suggestive positions that mimic adult pornography. All the other DVDs in the shop also feature real children.
"I feel sorry for the children," Kanajiri tells me.
These so-called "Junior Idol" DVDs became popular after the production of child pornography was outlawed in 1999. They dodged the law as long as the children's genitals were covered, but Kanajiri argues they're now illegal after the law was strengthened last June. But they are still on the shelves!!?? So, does anybody care enough to enforce the law?
"People who exploit should be punished properly," she says. "It's completely illegal under the law, but the police haven't cracked down."
While some of the content in manga and anime featuring minors in sexual situations might be shocking and attention-grabbing, Kanajiri and other campaigners I spoke to told me that for now, they are focused on more important battles to protect real children.
But she tells me she hasn't given up hope of a ban on contentious manga and anime.
"I want to make it disappear," she says. "By 2020, when the Summer Olympics will take place in Japan, we have to turn Japan into a country which people don't call a perverted culture."
It's a description which supporters of manga strongly reject. But as the Olympics approach, outside eyes will turn to Japan, exerting a powerful pressure for manga and anime to be part of what people see as "cool Japan" rather than "weird Japan".
It all seems like such a far cry from the pride and honour that had Japanese men falling on their swords rather than bringing dishonour to their family.