These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Muhyo And Roji
Counterpart Comparison: Despite being almost as far from Naruto in terms of personality as possible, Muhyo's quest to redeem Enchu has a fair number of parallels with Naruto's quest to bring Sasuke back. Both of their friends were also their rivals while they were still good, and turned evil in response to the death of a family member. Both heroes are detemined to bring their friends back or die trying.
Cult Classic: Despite not being nearly as popular as One Piece or Naruto, the story has a well established universe with very memorable characters.
Ensemble Darkhorse: Despite only appearing in a single volume that ends with her death, Panza ranked 6th in the second popularity poll.
Ebisu started out as a petty criminal until Goryo saved him after a ghost turned on him and took him into his service. He's completely unrepentant about his wrongdoing in the past, but it shows that he has been through quite a bit.
The Cortlaw siblings to various degrees. They collaborate with Ark to revive their parents, whom they believe were murdered by the Magical Law Society, in spite of their parents and themselves are not good people, at least by society's standards.
Memetic Molester: Tomas, at least in the Japanese fandom. He did try to abduct one of his students, for questionable reasons... so yeah.
Bulpu is even worse, he specifically wanted the youngest of the three Courtlaw siblings, Kid, a sweet boy compared to his siblings. This is more disturbing since Buhpu is the eldest, excluding Teeki for obvious reasons, and abuses the youngster's body and literally takes it for his own
The revelation that Teeki killed Enchu and Rio's mothers, causing them to turn evil, as well as the revelation that he killed the former's mother with the goal of taking his body.
Buhpu killing Ivy for her failure and using her death to manipulate her brother Kid into fighting the heroes by saying Goryo killed her after she was defeated.
An interesting case occurs with Yuki Otada. His crime, kidnapping, is enough to earn him a trip to Hell, but nevertheless, the cast continues to feel sympathy for him, with Muhyo giving him a Lotus-Eater Machine to ease his descent.
This to many of the ghosts, while could be seen as monsters at least at first, but once their Freudian Excuse is revealed, you realize they are suffering from their own sadness.
Enchu. Dear lord, Enchu, his entire Freudian Excuse was a scheme planned by his Evil Mentor, Teeki who just wanted a stronger body for immortality
Panza: She's bullied at school, essentially abandoned by her parents after she applies for MLS, and fails to become Muhyo's assistant, leaving her with nowhere to go. True to form, Teeki targets her when she's at her lowest point and turns her to his side.