The weakest guy's system

In a world where a system controls people's physical and mental abilities, and thus their destiny, allowing them to fight monsters found in dungeons, there is a boy, Yuki Takahashi, who suffers from several problems caused by this unfair system. He is a short and skinny boy with black hair covering his face, giving him such a dark aura that everyone avoids him. Suddenly, due to an accidental change in his system, he finds himself in unwanted and sometimes dangerous situations that can change his life and lead to new encounters. His adventures will change his life completely, and he will go from being the weakest guy in the world to someone who can actually hold his own with everyone else. How will Yuki Takahashi grow through his story?!