User blog comment:Xilinoc/Ch. 615 - All is Lost/@comment-5303512-20150212131419/@comment-5398287-20150213091408

Seinen is essentially a form of manga catering more to adults than to boys, which is what Shonen is. Think series like Attack on Titan, Gantz, and Kuroshitsuji, and you'll understand what I mean by everything going to hell if it makes the jump.