Another theme could be adventure - based. Given that they are from the Sonic universe which is full of action and adventure, the fanfiction might incorporate their relationship while they are on a quest or facing a common enemy. They might start off as reluctant allies and gradually develop deeper feelings for each other during the course of the adventure.
Chapter 48 is the strongest chapter-level answer because it starts from He Yun felt guilty for initially ignoring Jiang Li on purpose, and with... and follows through on Besides, everyone's phones will be replaced with special smartphones....
The best chapter pointer here is Chapter 73, "Does Someone Like Jiang Li Deserve to Have a Fan Club?". It opens with Director Sun, tongue-tied, finally managed to squeeze out a sentence,... and closes on Despite Wen Jiaojiao's fiery temper, there were still many who were drawn....
A practical answer is Chapter 38, because it turns the idea into a concrete scene. The chapter opens with Jiang Li had also observed the girl who had just entered., adds pressure through When did Jiang Li become so rational and composed?!, and ends on He Yun coldly turned his head and continued to.
A practical answer is Chapter 32, because it turns the idea into a concrete scene. The chapter opens with You should know, an ID photo is like a mirror for demons., adds pressure through This time, we bring six guests to travel to the distant Highland Mountain..., and ends on With airflow comes.
A practical answer is Chapter 84, because it turns the idea into a concrete scene. The chapter opens with When the villagers tasted his curry beef one by one, their faces revealed..., adds pressure through [Pfft, and she's teaching others how to cook, isn't it just scrambled eggs..., and ends on.
Chapter 75 is the strongest chapter-level answer because it starts from The ordinary people in the livestream were all stirred up by this scene. and follows through on But, being a half-baked practitioner is just fine..
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....
If you want the clearest chapter reference, go to Chapter 95. Early on, Hearing others praise her daughter, Aunt Lin was smiling so wide she...; later, the chapter leans on Lingling really is a good child..
The best chapter pointer here is Chapter 64, "The Morning Battle". It opens with Chixia Village lay in tranquil slumber. and closes on He'd been a host for so many years; he was used to it..
Look to Chapter 53 for the clearest answer. It begins with Night had fallen over Chixia Village, eerily void of any human sounds., keeps building through Jiang Li followed the village chief's wife down a narrow path leading to..., and lands on Wait, did this kid accidentally fall into the water?].