The plot might involve a search for a special key or trinket that is crucial in both the Kingdom Hearts universe and the world of The Little Mermaid. Ariel, being curious, could join Sora on this quest. Along the way, they encounter Ursula who has made a deal with the darkness from Kingdom Hearts. They have to battle her and her minions, all while Sora tries to keep Ariel safe and teach her about the power of the heart.
One possible plot could be that Sora and his friends land in the underwater world of The Little Mermaid. Ariel could be in trouble, perhaps captured by the Heartless. Sora, with his Keyblade, would fight to free her. Donald and Goofy could help by using their magic and strength respectively. They would then have to find a way to restore the underwater kingdom's heart which has been affected by the Heartless presence.
Well, in this crossover fanfiction, it could start with Ariel finding a strange object washed ashore that has a connection to Kingdom Hearts. This object attracts the Heartless to the underwater world. Sora and his companions sense the disturbance and come to investigate. They meet Ariel and her friends. Ariel is intrigued by Sora's Keyblade and his ability to fight the Heartless. Together, they embark on a journey to stop the spread of the Heartless in the ocean and also to find out how this strange connection between their two worlds came to be.
A practical answer is Chapter 66, because it turns the idea into a concrete scene. The chapter opens with I can't take it anymore, why did the young master even find a pair of..., adds pressure through If adults can't sort out their own breakfast, what good are they?, and ends on Unable to find a.
A practical answer is Chapter 135, because it turns the idea into a concrete scene. The chapter opens with The sun blazed down mercilessly, but thankfully, the path to the mountain..., adds pressure through At this moment, it seemed more likely to be grim than not., and ends on Are you healed from.
Look to Chapter 75 for the clearest answer. It begins with The ordinary people in the livestream were all stirred up by this scene., keeps building through [Did you see that, did you see that?, and lands on But, being a half-baked practitioner is just fine..
A practical answer is Chapter 115, because it turns the idea into a concrete scene. The chapter opens with Jiang Yan was woken by a loud crowing noise., adds pressure through Looking back now, the rebelliousness and obstinacy in his bones were..., and ends on [Pure bystander, wasn't Jiang Yan.
If you want the clearest chapter reference, go to Chapter 91. Early on, When Jiang Li saw that he had been assigned a harrow, Qi Tianyu felt his...; later, the chapter leans on My tool couldn't possibly be a shovel, could it?" Director Sun chuckled....
Chapter 102 is the strongest chapter-level answer because it starts from When the camera cut back, the three of them had already returned to the... and follows through on The cameraman, with a blank expression, turned off the camera, causing....
Chapter 108 is the strongest chapter-level answer because it starts from In a glamorous Michelin three-star restaurant, Su Yinwan and Shang... and follows through on Hey, I've been waiting for you for so long, where have you been?" Jiang Li....
A practical answer is Chapter 67, because it turns the idea into a concrete scene. The chapter opens with I'm pissed," Jiang Yan cursed again, "These people are too much, aren't..., adds pressure through And it's made by Jiang Li., and ends on Accompanied by the wisps of smoke gradually rising.
Look to Chapter 86 for the clearest answer. It begins with After over an hour of fuss, it was finally time to eat., keeps building through Qi Tianyu, starving, crazily scooped up his curry rice into his mouth., and lands on But then her expression became resolute and arrogant..
Chapter 87 is the strongest chapter-level answer because it starts from Luckily, at that time, Jiang Li had already taken her pot of stinky... and follows through on I'm driven crazy by him every day.] [+1 from above!.