Hobbies of the Rich
This sidequest will only open up once you have begun progress in the sidequest "From the Ground Up" to unlock Tarrey Town as a location on your map. Learn more about this sidequest here.
Talk to Hagie who is sitting out overlooking a large, swampy area on the shore of Lake Akkala. He will ask you to defeat two Guardians for him at Torin Wetland, where he is looking. He will pay you in advance with a silver Rupee and send you on your way.
Simply Paraglide towards the wetland and you will see an area that is absolutely littered with dead Guardians...and being patrolled by two fully alive, walking ones. You want to defeat those two Guardian Stalkers using whatever methods you prefer and then report back to Hagie.
Hagie will be busy at night so you will want to talk to him before the day closes to receive your final reward...a meager red Rupee. The total earnings for this sidequest is 120 Rupees. Not bad?