Korean pop idol group TVXQ has finally topped the Japanese music chart. Its 12th single 'Summer Dream' topped the Oricon daily single chart on the first day it was released Wednesday.

Excluding Ryu Si-won, whose acting fame boosted his chart rankings, the number one ranking is the first by Korean male singers. Heavyweight Japanese singers released their albums on the same day but they failed to rise above TVXQ.

The milestone comes 2 years 4 months after the pop idol group released their first Japanese single in April 2005. It also took pop icon BoA considerable time to reach the top of the Oricon chart.

But TVXQ's number one ranking was predicted from early on. Starting with its second single in July 2005, which made the top ten, all 13 of their albums including two regular ones had all entered the Oricon top ten. Their 11th album last month climbed to second place, indicating its likely number one ranking.