The Sony Xperia Z4, which was unveiled in Japan back in April and went on sale on June 10, has slipped out of the top five best-selling smartphones ) in the country.
The NTT docomo and au by KDDI variants of the device, which debuted at the number 1 and 2 spots, have slipped down to number 7 and 8, respectively. The top 5 spots are occupied by Apple's iPhones, while the Xperia Z3 Compact is in 6th place.
This shouldn't really come as a surprise, given that almost immediately after the Z4's release, users started complaining about overheating issues. Its international variant, the Xperia Z3+, is also plagued with similar issues. Meanwhile, Sony has promised that it will release an update to fix the problem sometime this summer.