another way to get one(only when you have the airship.) id when you meet clasko in macalania when you talk to him he asks if you think he should be a chocobo knight or chocobo breeder. if you say breeder later on when you get the airship you can get on one of the boats you went on earlier in the game(when you fougth sin for the first time.)then find clasko and hell give you a friend sphere.