Demon Slayer, while trailing at the start of sales, shoots up when the anime series ended and has overtaken where Bleach was in 2005 at 20 million copies sold in Japan.
With over 20 million copies sold as of Volume 17, Demon Slayer: Kimetsu no Yaiba is up there as one of the biggest manga ever, with rumors (and maths) that the series has sold more than One Piece manga volumes have this year.
Bleach would cross the 20 million copies sold mark at volume 18.