A girl in Hyrule Castle Town gives you a Happy Clover and tells you to give it to the king.
Where to Start the Quest
After you complete the quest "Still Missing", talk to the girl near the entrance to Hyrule Castle to start the quest.
How to Complete the Quest
Go north into the castle and talk to the king. After the cutscene, go to the south entrance of Hyrule Castle Town and talk to General Wright. Then go south across the bridge, and go along the dirt road. Talk to the soldiers along the path. When the soldiers tell you to go west, go west along the dirt road. Eventually you find more soldiers. Talk to them. Then go south along the dirt road and it will lead you to the entrance to the rift. There will be a cutscene. Check on the glowing spot in the rift, then check on the entrance.
Stilled Southern Hyrule Field
Find Tri's Friends, Part 1
Go northwest and you will see Romi. Go west and then northwest and defeat the Torch Slugs on the wall. Then climb up the wall and defeat the Mini-Moldorms, including the Dark Mini-Moldorm, which will drop a glowing object. Check on it to rescue one of Tri's friends.
Find Tri's Friends, Part 2
Go east and defeat the Peahats and the dark Zol, which drops a glowing object. Check on it to rescue another of Tri's friends.
Find Tri's Friends, Part 3
Go east, then south to some water. Defeat the Tanglers, including the Dark Tangler, which drops a glowing object. Check on it to rescue the last of Tri's friends.
There will be a cutscene. Tri's level gauge will increase. You receive 2 Might Crystals.
Quest Reward
After the cutscene, you receive the Customary Attire.