This is a sidequest available after you speak with the High-Chief of the Garif in Jahara, but it takes place in Rabanastre.
Head to the Southgate area of Rabanastre, and speak with the Viera near the chocobo stables. She will go on about how she is looking for a soul mate, and she is sure to find one in. Right. She will then wander off, leaving you to your own devices.
Now, head to the Southern Plaza, near the fountain in the middle should be a guy with "Lovestruck Man" written over his head. Speak with him, and he'll mention about a Viera walking past him towards the East Side of the city, and then he suggests how he wants to... hold hands and talk about the weather with her. Right. It seems that there are all sorts of people out in Rabanastre. As hinted, go through the east end, and then go to the north end and enter Yamoora's Gambits. You'll find the Viera, speak with her to then get another hint - that she needs a drink - and again will disappear. Of course, this means you must head to the only pub in the entire city (must be a city of teetotalers), the Sandsea.
In the Sandsea, the Viera is sitting on the railing on the second floor. She will ask you (finally!) if you know somebody who feels strongly for her, and as a matter of fact, we do! Get back to the Lovestruck Man in the Southern Plaza, speak with him (and agree to vouch that he is in no way a bunny-girl fetishist and that he is a decent guy looking for a soulmate), then get back to the Sandsea. Tell the Viera: "There's this guy in the Southern Plaza..." and she will hop of to see.
Go back to the Southern Plaza, to find them all lovey-dovey and the Viera worryingly confirming that this guy just may be the one... or the latest in a long line of close-misses. Either ways, you get a Loxley Bow (probably named after Robin Hood of Locksley) and 2x Hi-Potions.