O'aka XX is a recurring character in Yocun's Story, a traveling merchant who befriends the summoner party and consistently aid the group.
O'aka, just a traveling merchant, was on his way to Lake Macalania when he encountered a battle just recently begun between the summoner party and Maldus. He watched until Maldus disappeared and when he was noticed by Yocun, she asked him to go to Bevelle and inform Master Dammen of everything he saw. O'aka agreed and accompanied the group through the Macalania Woods.
As they traveled through the woods, O'aka entertained the group of stories of his ancestors, with Silva being the most interested. However, after Silva accidentally insulted Gillespie, the ensuing argument led to a confrontation with a sinspawn. Yocun managed to scare it away, but they knew they had to lure it back out and kill it before it could attack anyone else. O'aka suggested a place in the woods where one could stand as bait and the other could stand around in the trees.
They waited in the trees with Gillespie int he center as bait, but when he sinspawn attacked with its vine, the plan was sent into disarray when Silva was taken by the other vine. Yocun and O'aka followed the vine back to it source and after Yocun summoned Shiva to deal with the sinspawn, the other approached the injured Silva resting against a tree. Barton tried to heal her with an Esuna spell, but kept failing. O'aka offered him and antidote free of charge, but Barton only accepted it after it was obvious his Esuna spell wasn't going to work.
After the sinspawn was defeated, the group returned to the path and came to where the road forked one way to Bevelle and the other to the Thunder Plains. Yocun gave O'aka a letter which would give him access to the Measters and thanked him for his help int he woods before splitting off.