Daruk's Boot Camp
The quest is unlocked after completing the All Hyrule, United scenario.
"Yunobo wants to be just like Daruk, so he's giddy that the Champion himself has agreed to teach him how to use the power of Protection! Now, what can he give Daruk as a thank-you gift?"
"After plenty of intensive training with Daruk, Yunobo gained a much better grasp of the power of Protection! Plus, the Goron Champion was delighted by his descendant's thoughtful gift."