Many years after kh2 king Mickey retires and hands the crown to sora. He gets married with kairi, riku with namine ,and bhk with the brown haired girl. they all live in the Disney castle and peace in the world is complete. Sora has two boys Rie and Aros. Riku has a girl Sara and bhk has a boy matt.
One day (kh2) final boss is reborn and finds out how he can use sora’s heart to opened the door to kingdom hearts and so he looks for a way to get it. He tries to find a heart with darkness in the Disney castle so he can sneak in . So he starts looking into there hearts.
Rie & Sara start becoming more than just friends and aros starts getting jealous at his older brother. Then the villain gets a hold of aros and aros gets consumed by the darkness. At that night king Mickey (retired) gets a weird feeling . That night aros walks into sora and darkness surrounds sora and that’s when the villain tells him what he’s going to do. Sora then locks his heart and then spreads it through out the world as fragments . The villain becomes furies and enters into soras body and sets off. Aros comes conscious and kairi wakes up only to find a note with the king seal. It says that the only way to get him back is to find the fragments of his heart. And that he can already feel darkness seeping out of kh.
kairi gives the key blade of his father to rie and tells him to go find he’ fathers heart. King Mickey hands over his key blade to sara and tells her she should go . Matt gets the duel wielding key blades from his father goes as well. Donald Duck hand his staff to sara for extra help and Goofy hands his shield to matt for extra help as well .the staff and shield merge with the key blades and they become the wisdom blade and valor blade. So they set off to find King Sora. Aros heart starts filling with darkness as he sees his brother setting of in he’s own adventure. And hitches a ride with the villain. Only to become the rival of Rie.Will they find King Sora.
Kingdom Hearts
The Birth of a King