I think you're wrong. It's obvious he has something in plan, the moment he woke up Akamaru. He's obviously pretending to be the bad guy. Honestly..you kind of remind me of the main character. Naive. You judge people with how they act, but not with what they think. He's not cool like Akamru, who always saves her and he's always oblivious and late, but in his own ways he does his best. He's not considerate and he's incredibly stupid, but he's kind. He's already experiend the hardship of life. He had to sell his body to eat! So he doesn't know what's natural for a nomral kid. He's not ungrateful. The fact that he's letting The main girl, end up with Akamaru, means he's well aware that Akamaru is better for her. Even though he obviously likes her...He would let Akamaru end up with her! So he doesn't need you to tell him he's a 'piece of shit!' Cause he's more aware of that than you.

Wow what a piece of shit... She always helped him and even putted her life in danger for him and how he repays her? By turning his fucking back to her...
Ungrateful piece of shits like him don't deserve her. I just hope that when this clears up she won't return back to him. He deserves to be alone.