57 chapters of mindfuck masterpieces. Not a "tragedy" per se, but you'll definitely not forget the psychological issues this manga tackle in a hurry. The four main characters, though batshit insane have their own distinct personalities, actions and development and it's impossible to just either hate or love them. Might be off-putting for some, even for me at some points but still worth the read.
Two parts that depict the characters before and after their adolescence, both are equally addictive but the second part is just out of this world. My words can't describe how good this manga is but someone with a literate mind will find more in this manga.