I have been reading Kengo Hanazawa's work for the last month, going out of order of publication. Started with I Am A Hero, then Boys On The Run, and now Ressentiment.
I have to say that he has gotten tremendously more skilled as both a writer and artist in the 20+ years since he created Ressentiment but there are bits of his genius that are still apparent in this manga. Also although both the story and art were immature and somewhat crude in comparison to how good he is today, it's not like they were bad either. The concept here felt very creative (even if it was a bit half baked) and the art was often viscerally disgusting in an entertaining way whenever he drew panels of reality, ESPECIALLY all the gross ways he drew Takuro's obese, filthy, snot-covered, hairy-nippled body throughout the whole series.
If there is one thing Hanazawa is allergic to, it is writing anything remotely fan-pleasing; particularly his MCs are always some combination of pathetic, disgusting and infuriating. Unique to Ressentiment, however, I felt that Takuro deserved everything bad that happened to him and it was not nearly as frustrating to read as BOTR. It was kinda fun to be able to laugh at Takuro as he failed spectacularly again and again.
It was interesting to see that Hanazawa re-uses lots of ideas: his interest in mail slots on doors being one tiny yet distinct item he likes, among other things like re-using certain names (Aoyama, Yajima) and mentioning teleclubs. I know there were other things that made me go 'aha' when I saw them but I can't remember all of them.
All in all, I think this was the weakest of the three I've read, but that is forgivable since it is the oldest work.