At first, I had expected the main character (MC) to be mature, composed, and perhaps even somewhat cunning. During his childhood, he displayed those qualities, but then, rather abruptly, he fell in love with the leading lady (ML) in just one chapter. I suppose a bit of romance was necessary. However, after that, the MC's behavior became irrational. He threw tantrums and acted childishly, constantly dwelling on the fear of losing ML without taking proactive steps for his own survival. Given his lack of familial support, it would've been reasonable for him to develop new skills to ensure his well-being. Additionally, there was no resolution or retaliation against his unreliable and despicable father.
The character development was lacking; instead, he seemed to regress, becoming increasingly foolish, weak, and jealous throughout the story. It was quite frustrating to witness. And let's not forget, he was dense, to the point where it was almost painful for the reader to see how oblivious he was to ML's feelings.