Just finished the manga Oyasumi Punpun and I feel empty and lost now. It started off bright like the child Punpun was and ended so dark. Not going to spoil the whole story, but there will be many different events relatable to real life. It also includes betrayal, suicide, domestic violence, murder and sex, even though the main character looks like he is drawn by a kid. The story is deep and psychological, just like Aku no Hana, so you might like this if you read that.

Giving it a 9 out of 10.

On a different note, Kino no Tabi is rated pretty high on MAL so I assume it is worth checking out.