uhm
are you fucking serious ?

Boku wa mari no naka seems like a good manga from my first impression, definitely interesting

okay now it's getting weird

just finished himizu, great manga and i recommend it to anyone that can endure a bit more mature stuff

ma-mature ?, mature in which way ?

graphic violence and mild nudity

you won't find graphic violence and nudity in a manga made for kids and it's classified as 18+

what's mature about naruto lel

if you read himizu you'll understand it's much more mature than naruto

Read/watch Berserk, then read/watch Naruto. The former is clearly mature (excessive gore, nudity, rape and horse dick) and the latter, Naruto, is clearly intended for younger kids. Seinen and shounen labels exist for a reason. Mature anime/manga tackle darker themes too, like suicide and drug abuse (e.g. Holland).

To contribute to the thread, I just finished reading 20th/21st Century Boys. Very good mystery by the same guy that made Monster.