So many people have talked about this anime... You are right in what you mentioned at the beginning, since although at first this work was sold as a Shōnen, It wasn't until shortly after that it began to be classified as something a little more Seinen due to the themes related to abuse, suicide, etc. What's more, there is an episode of this anime (I don't remember well if it is 7 or 8) that was a craze on the internet because it tells us a tragic and very strong story of a mother and her daughter.

In short, outside of the absurd main plot that the anime has of a high school boy searching for his private parts with his new friend, We also see a background related to the secondary characters that makes it much more interesting than it already is. That, along with everything else; the high-level animation, the incredible soundtrack, the visual and sound effects and the varied battle and chase scenes it has make it a potentially promising anime.

Good review.