Robin is a character from Romancing SaGa 3. He is located in Yamas and is first seen in the quest called The Adventures of Robin. He protects Yamas and acts as a hero of sorts to the town stopping any crime or bad guys, He at one point also saves Fat Robin who with a failed attempt tried to be the hero. After the quest Robin can join by entering the warehouse where you first saw him stopping a crime when going in either Fat Robin will appear or he will appear sometimes. Simply exiting the building and entering again will eventually change up which Robin appears.
Robin (played by Yūta Ogasawaru) in Romancing SaGa the Stage: The Day Roanne Burned
Robin and Fat Robin from the Imperial SaGa animated PV Kaiketsu Robin no Tēma
Robin art featured in the Imperial SaGa x Crystal of Re:Union Collaboration event