One common theme is unrequited love. For example, Naruto might be jealous if the person he loves shows interest in someone else. Another theme is competition. He could be jealous of another ninja's skills or achievements that seem to overshadow his own.
The theme of envy of power also pops up often. Naruto, seeing others with unique or stronger powers, can become jealous. This jealousy then drives the plot as he tries to either match or surpass those powers. Additionally, the theme of possessiveness over a person or a position in the village can be found in many such fanfics. His jealousy might be about protecting what he thinks is rightfully his, whether it's a relationship or his status as a hero in the village.
The best chapter pointer here is Chapter 111, "From now on, Zhao Daniu is my new brother!". It opens with The main room's door was pushed open just a crack, and the head of the... and closes on This time it was in a dream..
The best chapter pointer here is Chapter 88, "I Call This a Test of Your Will!". It opens with She wanted to refuse, but didn't have the courage to do so. and closes on Let's go," Jiang Li said in a soft voice..
If you want the clearest chapter reference, go to Chapter 57. Early on, Lu Xingchao's numerous fans were stunned.; later, the chapter leans on Holy shit, what's up with God L?.
A practical answer is Chapter 58, because it turns the idea into a concrete scene. The chapter opens with Facing Jiang Yan's triple barrage of questions, Jiang Li's only response..., adds pressure through The cameraman, "......" [I'm dying of laughter, I was about to praise..., and ends on By ten.
The best chapter pointer here is Chapter 89, "Brother He, how can you be so unreasonable too?!". It opens with Director Sun took a step back, "What's the rush? and closes on If anyone should be mocking her, it should be me.] Wen Jiaojiao stood to....
The best chapter pointer here is Chapter 66, "This Sister Really Can Hustle!". It opens with I can't take it anymore, why did the young master even find a pair of... and closes on Unable to find a staff member to notify, and not wanting to waste time for....
If you want the clearest chapter reference, go to Chapter 54. Early on, Five minutes later, the people of Chixia Village, who had received the...; later, the chapter leans on Leading them was the village chief himself..
Look to Chapter 54 for the clearest answer. It begins with Five minutes later, the people of Chixia Village, who had received the..., keeps building through Leading them was the village chief himself., and lands on She was also polite and friendly, and to top it off, she was good-looking,....
Chapter 57 is the strongest chapter-level answer because it starts from Lu Xingchao's numerous fans were stunned. and follows through on I'm saying, big bro, can you at least reply to me?.
Look to Chapter 64 for the clearest answer. It begins with Chixia Village lay in tranquil slumber., keeps building through Gray clouds embraced the green mountain mist, shrouded in a gauzy blur,..., and lands on He'd been a host for so many years; he was used to it..