When Kairi lost her heart, Sora sacrficed himself then gave it to her. She was alive, but Sora turned into a heartless in the process. Kairi then gave a bit of her heart (which was his) to him.
Kairi never actually became a Heartless, but you're referring to what happened in Hollow Bastion's castle. Sora's and Kairi's hearts were linked, so Naminé was created when Sora sacrificed his own heart.
Sora and Kairi's hearts are linked, so when sora became heartless to save kairi, he also created namine' as a special witchcraft nobody True, but Kairi never turned into a Heartless because she had all light in her heart. Her heart couldn't go into darkness, so it went to Sora instead.
Kairi?
Kairi's heart is used for summoning Kingdom Hearts for her purity. Sora vanquishes his own heart to revive Kairi but turns into a Heartless and creates Roxas (Sora's Nobody) and Naminé (Sora and Kairi's Nobody) in the process.
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In the first Kingdom Hearts as well as chain of memories: Sora: 14 Kairi: 14 Riku: 15 In Kingdom Hearts II: Sora: 15 Kairi: 15 Riku: 16 (as well as 358 1/2 days) In Birth By Sleep: Sora: 4 Kairi: 4 Riku: 5
Firstly, it's not Kingdom Hearts 3, it's Kingdom Hearts: Birth by Sleep, made for the PSP console.Secondly, they aren't Sora, Kairi and Riku - they're Ven, Aqua and Terra. Supposedly, they're counterparts to the three though and somehow linked to them.
Namine is Kairi's Nobody. She was created when Kairi's heart went into Sora in the beginning.
Well, Kairi doesn't actually have a Heartess...but Namine is her "Nobody". According to the game a "Heartless" is made when a person yields to darkness and the vessel that has been left with no heart becomes a "Nobody". If you can remember at KH1, Sora gave up his heart for Kairi turning him into a heartless. Since Kairi lost her heart and didn't become a Heartless, she only has a Nobody which is Namine.(my theory for Namine's ability to control the memories of Sora's heart was because of Kairi having Sora's heart and vice versa, their hearts are directly linked.
Sora, Kairi, Riku, Donald, and Goofy!
they do twice at destiny island and when Sora turns to a heartless
I really think so but everybody knows that sora and kairi are the perfect couple