Sony's PlayStation Vita saw a 78 per cent drop in sales figures in its first two weeks, from 324,859 sold in week one to 72,479 in week two.
This allowed older consoles, the PlayStation Portable and the Nintendo 3DS, to actually outsell the new machine in week two, with the 3DS hitting 482,200 sales and the PSP 101,121.
The handheld launched in Japan just before Christmas on December 17 and the figures came from researcher Media Create.
Sony Japan itself has refused to comment on any sales figures.
By comparison the Nintendo 3DS sold 374,764 in its launch weekend in Japan, while the Vita's predecessor, PSPgo, sold 166,074.
It's still early days for the machine in Japan, and the drop in sales could be attributed to both the high price, which is set at 24,000 yen, to the lack of a Monster Hunter launch title, a key franchise for the console in the Japanese market.
Some are now speculating that the sales will force a price cut for the machine.
Elsewhere in the industry developers and publishers have remained sceptical about the console's chances in a market dominated by mobile and tablet devices, with Dr Mike Capps of Epic Games the most recent.
"I'm not sure how well it's going to be accepted in our Western market which is primarily where our games sell," he said in an exclusive interview.
"It's a really cool platform, but I have a phone, and it's really hard to compete with that. So I'm not sure if it will be successful or not."
The Vita will launch in the UK on February 22, priced at round £230.