Sony’s games chief said this week that a lack of locally produced games has meant that the PlayStation 4 is doing just “OK” in the Japanese market.

The PS4 has been a spectacular success on a global basis since its launch in November, with more than 7 million systems sold. It is selling at a faster rate than the PlayStation 2 and the PlayStation 3 did during their launch years. And it is outselling Microsoft’s Xbox One.

But in Japan, the PS4 has sold only 620,000 systems in four months. Sony Computer Entertainment president and group CEO Andrew House told Eurogamer at the Develop conference this week, “It’s doing OK.

“We’re conscious of the fact we have not had yet the sort of groundswell of Japan native content from Japanese publishers and developers. I view that as temporary.”

The PS4’s success elsewhere could convince Japanese companies to throw more support behind the PS4. But it’s worth noting that in Japan, mobile games are doing extremely well. Tokyo is covered with advertisements for mobile games, and that means that the revenues coming in from those games justify big advertising spends. House also said that the PS3 continues to sell well in Japan.

The weakness of the PS4 in Japan might give Nintendo more breathing room to sell the Wii U as more big games for that system arrive.