Kingdom Hearts is a series created by Square Enix and funded by Disney, which is why characters from boh the Final Fantasy series and Disney characters show up.
The games revolve mostly around Sore and his friends Rikku and Kairi. Sora gets a weapon known as a Keyblade which he uses to fight beings known as Heartless. He meets various Disney characters and has many adventures, saving the world and his friends a few times.
