In 1996, game designer Satoshi Tajiri pitches a new idea to his Nintendo bosses. In part, he'd been inspired by his childhood hobby of insect collecting.
After Japanese cities grew, and bug-collecting hot spots were paved over, Tajiri wanted kids to have the same thrill of catching and collecting creatures as he'd had. Neighbours' pets were out of the question because that's called kidnapping.
His idea involved fantastical creatures called Pokémon. It would soon turn into a global obsession with video games, merchandise, strategy guides, movies, and, of course, trading cards that have raked in more than $150 billion.
Today's generation of kids is just as obsessed as the one before. The cards are so big that some New Zealand schools have even organised Pokémon trading clubs.
Peninsula Primary School principal Brenda Cronin said they give students a unique opportunity to learn positive behaviours. "I think parents should be really excited their kids are learning some of these rules around sharing and being kind. I think it's brilliant."
Right now, if you throw the word "Pokémon" into Trade Me's search function you'll get about 6600 results, with some cards being sold for as much as $9000. That's still a far cry from what YouTuber Logan Paul spent earlier this year on the world's most expensive card - $8.5 million.
One of New Zealand's biggest collectors is Chris Chen. He got into them at the age of nine and, 20 years later, he's got a few lying around.
"I've roughly got half a million Pokémon cards in my possession," Chen told The Project. "Some of them I keep in card boxes and others in binders. For the higher value ones I keep in security vaults [at the bank]."
Over the years, he has spent around half a million dollars but estimates the current value of his collection is well into seven figures. And he gets a kick out of meeting other traders.
"They're like lawyers, accountants, surgeons, and policemen," Chen told The Project. "It's exciting to collect, and it brings out the inner child in me. The investment side is a bit of a bonus."
If someone in your home is collecting these, you should know the odd card can be worth quite a lot. There are internet sources to look up values, but Chen has a few tips to help novices work out which ones are "rare" (read: valuable).
"You will be looking for the ones that have the star symbol at the lower corners." Keep an eye out for the shiny, colourful cards too. "The rare cards tend to be holofoil."
Chen said it's worth checking any ones you've got at home because you could be holding onto a small fortune.
"One of my cards at the moment, the most valuable one, it was recently sold for about $30,000."