From the Super Mario Wiki
“Huh?!?! You want this, amigo? This little rock over here? Are you serious? Well, that's no big deal... Here, take it. What do I need one or two extra gems for? I did not really like that one, anyway.”
The Sapphire Star is the fifth of the Crystal Stars Mario collects in Paper Mario: The Thousand-Year Door. According to the legend of the Crystal Stars as told by Grifty, the Sapphire Star was brought to Keelhaul Key by the tired Koopa hero in an effort to keep it safe. However, the pirate Cortez stole the star from him easily, and has since kept it in his treasure hoard. After being shipwrecked on Keelhaul Key and navigating Pirate's Grotto, Mario encounters Cortez and battles him for the Sapphire Star. After the battle, Cortez gives it up willingly, stating he didn't even like it nor need it. The Sapphire Star teaches Mario the move Sweet Feast to use in battles.
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