In the Japanese magazine “Nikkei Entertainment! K-Pop Bible” – Issue 6/29, a ranking of K-pop artists with highest total sales of Japanese singles, albums and DVDs was revealed.
Despite their two years hiatus, TVXQ or as known by Tohoshinki in Japan, came at the top with 1,749,276
Yen |Edit: number of units, not yen|!
Based on an article by The Fact Japan, it seems that this ranking includes accumulated sales from 2012/12/31 to 2017/04/30.