The Shueisha manga series “Kimi ni Todoke” (君に届け) Vol. 20 is currently the #1 selling manga in Japan with over 387,520 copies sold.
The shojo manga is written and illustrated by mangaka Karuho Shiina and has been serialzied in Shueisha’s “Bessatsu Margaret” since 2005 and was the winner of the “Best Shojo Manga Award” in the 32nd annual Kodansha Manga Award back in 2008.
In the U.S., the manga series is released by Viz Media.
#2 goes to Kodansha’s “Vagabond” vol. 36 by Takehiko Inoue which sold 248,629 copies (also released in the U.S. by Viz Media), followed by the release of “Uchyuu Kodai” (宇宙兄弟) vol. 22 written by Chuya Koyama with 238,039 copies sold.
Source: Oricon Manga Weekly Charts