their latest offerings, with special areas in the vast Makuhari Messe convention centre set aside for romance simulation games, cloud gaming and the booming smartphone and tablet game sector.
Around 200,000 people were expected at the event, which runs until Sunday just outside the Japanese capital, with many relishing the chance to get their hands on the new consoles from Sony and Microsoft.
The home-grown PlayStation 4 hits shelves in North America in November, in time for the holiday shopping season, but will not be available to Japanese buyers until February.
Visitors lay on pillows to play the videogame console and tablet holder "Goron", produced by Japan's Sanyo Precision at the Tokyo Game Show in Chiba. Photo: AFP / Yoshikazu Tsuno
Sony announced the roll-out earlier this month, seven years after PlayStation 3 debuted. It will be the first time the company's home market will not take the lead.
Company bosses said Japanese developers had been slower to exploit the potential of the new console and Sony wanted to wait until the software was ready before unleashing their latest offering.
For the original PlayStation, 18.6 % of global sales were in Japan. Its successor, the PlayStation 2, tallied 14.7 % of sales at home, while the PS3 racked up 11.9 %, according to data from VGChartz Network.
North America, by comparison, accounted for about one-third of all PlayStation sales.
A visitor looks at Sony Corp's new PlayStation 4 game console at the Tokyo Game Show in Chiba, east of Tokyo. Photo: Reuters/Yuya Shino
The new PlayStation will sell for just under 40,000 yen ($400) in Japan, about the same as in the United States.
The rival Xbox One, meanwhile, will be rolled out in 13 countries, including the US, Britain and Australia, on November 22. No date has been set for its release in Japan, although it will reportedly not be before 2014.
Experts say that while a hardcore of gamers will likely never forsake them, consoles have found their market share squeezed by the spread of smartphone and tablet gaming.
Free-to-play offerings on those platforms tempt casual users not willing to shell out $50-plus for a title on a dedicated machine.
Andrew House, president and group CEO of Sony Computer Entertainment, told convention-goers in fluent Japanese Thursday that the PlayStation 4 had been developed to make it competitive in the new world of gaming.
Models dressed as videogame characters pose for photos at the Tokyo Game Show in Chiba, suburban Tokyo. Photo: AFP / Yoshikazu Tsuno
"For game consoles to be at the centre of the home they need to have high quality content which all family members, from children to adults, can enjoy," he said.
"Also important is to offer the experience of social networking... we have really pushed the status of games to that of films and TV.
"In our next generation PS4, we have added new functions and services," he said, including networking with other game players through smartphones and tablets.
The Tokyo Game Show is open to media and industry professionals on Thursday and Friday. General admission begins Saturday.
Visitors try out new GungHo Online Entertainment Inc's new game "Puzzle & Dragons Z" on Nintendo 3DS at the Tokyo Game Show in Chiba. Photo: Reuters/Yuya Shino