LeaIsa

LeaIsa is the slash ship between Lea/Axel and Isa/Saïx from the Kingdom Hearts fandom.

Kingdom Hearts: Birth by Sleep
Lea and Isa both lived in Radiant Garden and were best friends. They always got into trouble together. One day, they encountered a boy named Ventus. Lea befriended Ven while Isa thought that it was odd that Lea wanted to make so many friends. Lea comments that he was a lot of friends so that he is never forgotten while Isa admits that he could not forget Lea if he tried. The two then left towards Ansem's Castle. They were caught at some point and thrown out by Dilan. They also buy sea-salt ice cream and eat it together.

At some point, Lea and Isa are turned into heartless. Their strong will also caused nobodies looking exactly like them to be created. Xemnas recruited their nobodies and named them Saïx and Axel. They were made numbers VII and VIII of Organization XIII respectively. Axel and Saïx are friends as they retained the memories of Lea and Isa. They also made plans to eventually take over Organization XIII for themselves.

Kingdom Hearts: 358/2 Days
Roxas eventually joins Organization XIII and Axel befriends him. He slowly begins to acquire a heart because of this. Axel also uses his friendship with Saïx to manipulate him into doing things for them such as allowing Roxas and Xion to be on missions together. As Axel goes closer to Roxas, he begins to drift farther from Saïx. By the time that Roxas left the organization, Saïx gave up on his plans with Axel as he believed that it was just a fantasy and that Axel had changed too much.

Kingdom Hearts II
Axel initially continued to be loyal to the organization but eventually left in order to help Sora whom Roxas had merged with by that point. Saïx later interrupts a conversation between Sora and Axel which forces the latter to flee. He assured Sora that Axel will be given the maximum punishment. Axel eventually sacrificed his life to help Sora get into the World that Never Was and he eventually destroyed Saïx.

Kingdom Hearts: Dream Drop Distance
Lea and Isa eventually appear whole again in Radiant Garden and wake up where they were turned into Heartless. Braig and Isa wake up first and flee the scene. Isa ends up taking the name Saïx and joins up with Master Xehanort. Lea then wakes up and immediately wonders where Isa is. Ienzo tells Lea that Isa can't be whole but Lea still insists on looking for him. Lea later saves Sora from becoming another vessel for Xehanort and Saïx eventually attacks him, revealing that he is willing to become a vessel for Xehanort. Lea is shocked and saddened by this.

Kingdom Hearts III
On the evening before the final battle, Lea sits upon the clock tower in Twilight Town, holding 3 sea-salt ice creams. Out of seemingly nowhere, Saïx appears, and sits by Lea, talking about the reason they were in the Organisation, to find Subject X. Snatching an ice cream from Lea in the process. Despite being quite mad, it seemed Lea didn't mind the company of his childhood friend, nor did it feel bad for Saïx aswell.

Later on, during the final fights, Lea tries to knock sense into Saïx, even spilling Saïx's former name, Isa, out, yet Lea is inevitably knocked down.

In the ending of the fight, just as Saïx was fading away, Lea rushed to his side. This was the turning point, admitting he was jealous, that he felt left behind, that he wanted to stay with Lea. Lea, admits he never forgot him. After this little interaction, Saïx is struck with a sudden pain, admitting to Lea he will never admit to being jealous again, and just like that, he falls into Lea's arms. Lea whispers "See you, Isa" and with a smile, Saïx whispers, "See you, Lea" before fading off.

After Xehanort's defeat, Lea and Roxas sit on the clock tower, Xion shortly joining, then the newly, re-completed Isa, appears with 3 ice creams in one hand, intended for the trio. Next to Lea, Isa sits by his friend, sharing the ice cream with the group.

Once Riku picks the group up in the Gummi Ship, the ending is shown with Isa, Lea and Ventus playing with the frisbee from their childhoods.

Honourable mention: The fan English translation of Saïx's character files, reveal he had a strong bond towards Lea, admitting it was relaxing to eat sea-salt ice cream just like when they were children, expecting this to be a still remaining feature for their future to come together. Saïx also refers to Lea as "crybaby", ending off the File with "that's your speciality, Crybaby, Despite everything. Our eyes take in the sunset."

Fanon
LeaIsa is a very popular Kingdom Hearts slash ship but is not quite as popular as AkuRoku or XemSai. However, it is still very popular. This especially became the case when it was revealed that Axel and Saïx were once very good friends until Roxas came between them. Once Lea and Isa were introduced as best friends in Kingdom Hearts Birth by Sleep, support for this pairing increased further. Some fans hope that Isa can still be saved as they do not believe that he really wants to become a vessel for Xehanort.

Fans have greatly shipped LeaIsa after Kingdom Hearts 3 revealed key details about how Saïx felt, the fanbase are hoping that they'd get to see future developments of the LeaIsa relationship.

Fandom
FAN FICTION
 * Axel/Saïx tag on FanFiction.Net
 * Axel/Saïx tag on FanFiction.Net
 * Axel/Saïx tag on FanFiction.Net

Trivia

 * Lea/Axel and Isa/Saïx are thought to represent the sun and the moon, even though Lea/Axel's element is only fire and not explicitly the sun.
 * Isa was the first person Lea shared ice cream with, after buying it from Scrooge McDuck in the Birth by Sleep credits.
 * The "death" scene of Saïx in Kingdom Hearts 3, seems to be Isa and Lea's version of the Xion death with Roxas in 358/2 days.
 * Axel and Saïx have both served as Number VIII of Organization XIII, Axel was Number VIII of the original Organization XIII whereas Saïx was Number VIII of the true Organization XIII.