Flown the Coop
Talk to Cado at Kakariko Village. He's standing by his chicken coop freaking out. He lost his Cuccos. Help him find them all. The Cuccos are all scattered inside Kakariko Village, so you won't have to go far. You will have to carry the Cuccos physically into the coop.
Cado says that he has 10 Cuccos total. Three of them are actually already in the coop, so you only need to track down the last seven.
If you are having trouble finding the Cuccos, complete "Slated for Upgrades" at Hateno Village and then set Cuccos with your upgraded Sheikah Sensor. You can learn about how to upgrade your Sheikah Slate here.
The locations of the Cuccos are as follows: -- By the fireplace near the Goddess Statue near Pikango -- By a bridge near the entrance of the village in someone's backyard -- On the path that leads to Ta'loh Naeg Shrine -- On the roof of the armor store -- In the garden with the cherry blossoms near the armor store -- On top of a shed near the entrance of the village -- Inside a shed on the south side of town
After you've tracked down all seven Cuccos and returned them to Cado's coop, speak with Cado. He will give you a purple Rupee worth 50 Rupees for your troubles.
This sidequest is a prerequisite for the following sidequests, which you can click on to learn more about: