Black Butler, Hetalia: Axis Powers, and Rosario + Vampire: Season II were the only three titles to reach the top rank on the week of their series debut.
Black Butler was the first release published by Yen Press to reach the top rank.
[1] Gustines observed that the week 45 releases of Bakuman, D.Gray-man, and Otomen demonstrated the diversity of the Viz Media's publishing line.
Bakuman features a slice of life story, D.Gray-man contains demon-slaying, while Otomen is a romance series.
[4] Week 19 was also the first time a Naruto release did not appear in the top ten rankings.