Gaddison shows you a fort that monsters have built at Ja'Abu Ridge.
Quest Location
Talk to Gaddison at the east bridge of Zora's Domain to start the quest.
How to Complete the Quest
Go to the fort and defeat all the monsters there. You will encounter Blue Bokoblins, some Silver Bokoblins (including one that is wearing armor) and a Silver Boss Bokoblin.
After the monsters are gone, be sure to lift up the cages to free Hino. Talk to him to get Salt-Grilled Meat, Sneaky Meat and Seafood Fry, and Fairy Tonic.
Quest Reward
Afterward, report to Gaddison to get 100 rupees.