Follow Rikku and Paine in their tracks - their location will be marked by a blue encircled arrow on the minimap. Each time you arrive at marked destination, a scene will occur. After you view second one and you have Yuna run S, you *must* see a scene where Rikku lands on her butt. After viewing third scene in total, chocobo escapes again. Just you wait! Go all the way to South exit of 'H - S end'(to Luca) - talk to the nearby female Al Bhed twice and pick [Please, yes!]. Chocobo is yours at last.