One plot idea could be that Naruto is somehow transported to the world of Final Fantasy 13. There, he meets the characters and due to his unique abilities and charm, a harem starts to form around him. He could use his ninja skills to help the characters in their battles against the fal'Cie. Another idea is that the characters from Final Fantasy 13 are brought to the Naruto world. The different cultures and powers collide, and as the FF13 characters adjust, they are drawn to Naruto, creating a harem situation. The harem members could then team up with Naruto to protect both worlds from common threats.
In a harem fanfiction of Naruto and Final Fantasy 13, the story could start with Naruto being summoned by a powerful being in the FF13 world. The female characters there see him as a strange yet powerful ally. Lightning, for example, might be initially skeptical but gradually come to respect Naruto. Fang could be intrigued by his physical strength. As they interact more, a harem dynamic develops. Naruto's goal could be to find a way back home while also helping the FF13 characters with their fight against oppression. Along the way, romantic and comical situations can occur within the harem.
Chapter 340, "Seclusion, Growth of the Yu Generation, Family Banquet, Rapid Development (Part 3)", is the clearest early answer because it turns Xia Yuyao's situation into a concrete plot event. The setup is Dad..." "Dad..." The two little ones, no longer restricted,..., but the pressure keeps building through Of course, because their walking was still unsteady, it was more of a....
Chapter 177, "You Annoy Me Just By Being Here", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. The chapter turns that into something concrete by moving from I'm actually the last?!" After the scores were announced, Wen...
Chapter 345, "Audition: She Couldn't Have Gotten in Through Backdoor Connections, Could She?", is the clearest early answer because it turns Director Zhang's situation into a concrete plot event.
Chapter 243, "How Could It Be Her?!", is the clearest early answer because it turns Wen Jiaojiao's situation into a concrete plot event.
Chapter 322, "Water Breaks Heaven's Heart", is the clearest early answer because it turns Zhang Cheng's situation into a concrete plot event. The chapter gives readers a real answer by opening on This character is great!" Tang Yuli was also very happy, "It just so...
Chapter 475, "Doting on the Man You Love to the Fullest", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from On the other side, Jiang Yan and Shang Shuyue also set off.
Chapter 263, "Jiang Li Won the Medal for Outstanding Individual?!", is the clearest early answer because it turns Director Sun's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Southwest Wildlife Protection Association V: On the evening of July...
Chapter 48, "All the Bitter Teas Have Been Taken Away", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from He Yun felt guilty for initially ignoring Jiang Li on purpose, and...
Chapter 454, "Are these two people crazy?!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. It opens with Shang Shuyue felt that following Jiang Li was the best decision she... and closes on Alright, next we'll go for training!" Yu Li: ?.
Chapter 288, "The Old Master Already Knows", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. Early on, Jiang Li and Zhao Lang were lifted onto stretchers and taken to....