This event can be triggered after Bur Omisace. In central section of Rabanastre, there's a man who's fall in love with the Viera warrior.

Talk to this man by the fountain, knowing that Viera is around.



Now go to South Entrance, talk to the Viera there.


Move to Northern street, enter the Gambit Shop and talk to the Viera inside
the shop.


Go to The Sandsea now, head up to the stage and talk to the Viera there.


After that, back to central section and talk to the man by the fountain again. Then return to The Sandsea and talk to the Viera, and she will leave.

Lastly, head to central section, you will see both of them are chating near the fountain, speak with them for your rewards, they are Rocsley Bow and Hi-Potion x2.