At the beginning the protagonist should be extremely pathetic and pitiful (not very pitaible) to the point that you (almost) don't want to root for him. The character must improve through a lot of hard work (if it doesn't take much to fix his problems then he probably wasn't that messed up/weak/pathetic to begin with)
Examples:
[Warning: due to the nature of this topic there may be some unintentional, unmarked spoilers. But I actually made this a spoiler for the "tl;dr" people. If it bothers anyone I will get rid of the spoiler warning thing]
Spoiler (mouse over to view)
Boys on the Run - Top of the list for pathetic protagonists in my book, although it hasn't been completely scanilated so I'm not sure if he becomes strong (it does seem to be heading in that general direction… probably)
Gantz - This is very much what I mean in the sense that in the beginning the protagonist was a very selfish person who I lacked sympathy for; but in the end he became a good leader.
Green Boy - Though it is a weak-to-strong manga with character development, the main character isn't THAT pathetic initially (that's to say he isn't bullied, considering suicide, or in a life or death situation [yet]). Though not the best example, it works. He has to rely on the girl a lot.
The Breaker - This character goes from pathetic and bullied to strong with the help of his master.
Fly, Daddy, Fly - average salaryman learns to fight for his daughter's sake. The character viewed himself as being athetic for not being able to protect his daughter. His desire for revenge leads him to completely change his way of thinking.
Attaque - Kind of an interesting twist, the protagonist used to be strong but now is pretty pathetic compared to his former self. He, himself isn't bullied but he is unable to do anything in a fight because of his injured hand and he longs to regain a sense of strength, but in the beginning he clearly is struggling to deal with his loss of power and is forced to bow down to those who are stronger than him while hearing to regain his strength.
Gekiryuuchi - Bullied, sucidal boy becomes a street fighter..I think (it's been a while)
Liar Game - The female protagonist is initially very idealistic and naive, but she learns as she plays the liar game. and becomes someone who doesn't foolishly trust everyone
RRR - The protagonist, Ricky, changes from a good-for-nothing, washed-up musician into a great father and boxer
Hajime no Ippo - The titular character has the the strength required to become a boxer from the beginning as a result of helping out at the family business. The reason that he is bullied is not because he lacks physical strength; it is because of his weak attitude. This still works because he was helpless at the beginning even though he didn't lack physical strength (this is even more pathetic in my book)
Gantz - This is very much what I mean in the sense that in the beginning the protagonist was a very selfish person who I lacked sympathy for; but in the end he became a good leader.
Green Boy - Though it is a weak-to-strong manga with character development, the main character isn't THAT pathetic initially (that's to say he isn't bullied, considering suicide, or in a life or death situation [yet]). Though not the best example, it works. He has to rely on the girl a lot.
The Breaker - This character goes from pathetic and bullied to strong with the help of his master.
Fly, Daddy, Fly - average salaryman learns to fight for his daughter's sake. The character viewed himself as being athetic for not being able to protect his daughter. His desire for revenge leads him to completely change his way of thinking.
Attaque - Kind of an interesting twist, the protagonist used to be strong but now is pretty pathetic compared to his former self. He, himself isn't bullied but he is unable to do anything in a fight because of his injured hand and he longs to regain a sense of strength, but in the beginning he clearly is struggling to deal with his loss of power and is forced to bow down to those who are stronger than him while hearing to regain his strength.
Gekiryuuchi - Bullied, sucidal boy becomes a street fighter..I think (it's been a while)
Liar Game - The female protagonist is initially very idealistic and naive, but she learns as she plays the liar game. and becomes someone who doesn't foolishly trust everyone
RRR - The protagonist, Ricky, changes from a good-for-nothing, washed-up musician into a great father and boxer
Hajime no Ippo - The titular character has the the strength required to become a boxer from the beginning as a result of helping out at the family business. The reason that he is bullied is not because he lacks physical strength; it is because of his weak attitude. This still works because he was helpless at the beginning even though he didn't lack physical strength (this is even more pathetic in my book)
Feel free to mention anything (on my list or otherwise) that way this thread can be helpful to the people of the future!
It would be much appreciated if you would explain your answer