Fly Merry Fly
Summary: Usopp has the best lullabies.
Each of Harry's 'aunts and uncles' had their own talents that made them special to him. Like how Chopper was best at cuddling while Zoro was the best babysitter (no matter how much Sanji denied it).
But, in Harry's opinion, Usopp had the best lullbies.
Sure, Brooke was a famous rockstar, but Usopp sang songs that filled Harry's dreams and occasionally brought a tear to Kaya's eye.
Harry and Kaya's favorite was about Merry, a ship that flew in the sky before meeting a tragic end where it was comforted by its friends. Usopp occasionally changed the ending so that Merry either flew off into the sky forever or became a great lion that traveled to the end of the world.
Sometimes, Harry felt like he was missing something important, especially when Usopp and Kaya shared a look that only adults seemed able to understand. Robin and Franky, as well as Nami and Sanji, often shared these looks when Harry wasn't supposed to know something because he was too little.
But even if Harry was missing something, he didn't care just as long as he got to hear more stories about the Merry-go's adventures, which left him dreaming about angel sheep and sky islands.
OMAKE
"Eh?!" Harry gaped, sitting in Kaya and Usopp's mansion. It hadn't changed much since his childhood and it felt good to be back. "Merry was real?!"
"I thought that you figured it out already." Usopp said, an exasperated expression on his face. "It's not like we kept it a secret."
"Wait!" Harry said suddenly, eyes widening. "What about Sogeking?! Was he real too? What else have you been keeping from me? Is Chopper secretly a superhero called Chopperman?!"
Usopp just facepalmed.
A/N: I'm taking prompts for the Papa!Sanji and chibi!Harry universe!