Well, a lot of Harry and Niall fanfiction has the theme of shared memories. They've been through so much together in their real - life band journey, and in fanfictions, these memories are often revisited and expanded upon. There's also the theme of discovery, like they might discover a new passion or a hidden talent in each other. And the theme of family - not just in a literal sense but in terms of the bond they have that's as strong as family.
Friendship is a very common theme. Since they were in the same band, many fanfictions explore how they support and care for each other. Another common theme is music. Fanfictions often feature them writing songs together or inspiring each other musically.
A practical answer is Chapter 22, because it turns the idea into a concrete scene. The chapter opens with Hearing this, Su Yinwan looked at Shang Shaojing with a face full of..., adds pressure through Why are you yelling so loudly?, and ends on Jiang Li's righteousness temporarily shut Jiang Yan.
Chapter 840, "How did you meet Miss Jiang?", is the clearest early answer because it turns Zhao Lang's situation into a concrete plot event.
Chapter 36 is the strongest chapter-level answer because it starts from But soon, people began to question the authenticity of Jiang Li's bare... and follows through on After swallowing the food in his mouth, he hurriedly took his megaphone....
Chapter 886, "Stinky Beggar", is the clearest early answer because it turns Capital's situation into a concrete plot event. The chapter turns that into something concrete by moving from After speaking, Jiang Li stepped forward and said, "I'll treat this...
Look to Chapter 37 for the clearest answer. It begins with The barrage was suddenly filled with hahas, but the two guests present..., keeps building through He Yun spent most of her time filming movies, had no interest in variety..., and lands on I look forward to your guidance." He Yun nodded.
Chapter 854, "These Brothers Are Quite Lacking in Love", is the clearest early answer because it turns Jiang Cheng's situation into a concrete plot event. The chapter turns that into something concrete by moving from If this bracelet gets bumped anywhere, she'll be heartbroken, right?
Look to Chapter 16 for the clearest answer. It begins with Just as the words fell, Jiang Shixu swiftly cast his eyes downward., keeps building through His eyelashes were very long;
Chapter 858, "If You Dare, Take It", is the clearest early answer because it turns Weibo's situation into a concrete plot event. It opens with Changqing flicked his horsetail whisk, face wooden, and said,... and closes on When is it going to be completed so I can visit?] [Whoa, it's....
A practical answer is Chapter 8, because it turns the idea into a concrete scene. The chapter opens with The resentment that had barely calmed among the crowd surged back two..., adds pressure through Why keep harping on the fact that he wasn't a decent man?, and ends on Other people with a.