YamaLu

Luffato is the Slash ship between Monkey D. Luffy and Yamato from the One Piece fandom.

Canon
Yamamoto gets along with Luffy, and has great respect for his strength and courage. Luffy, likewise, sees Yamoto as a great ally and friend. Yamato declared that he would sail across the sea with Luffy upon meeting his father.

Luffy refers to Yamato by the nickname "Yama-o", though he doesn't understand and often corrects Luffy when he calls him that.

Fanon
The ship has gained a noticeable following after the introduction of Yamato. Fans of the ship appreciate the subtle treatment of Yamato identifying as a male, despite being born a woman.