Assassination Classroom, about a middle school class who have one year to learn how to assassinate their alien teach or he'll annihilate Earth, was the break out hit of 2012 from Shonen Jump. Now, for this year's 21st issue, Jump has included a set of "All Star" stickers with alien Koro parodying the magazine's leads.
Digital versions can be picked up for the Japanese iOS Jump Camera - which lets users turn photos into Jump covers.
Saiki Kusuo no Psi Nan
A bit of Assassination Classroom itself...