This characters are part of the story, but they aren't able to be used in battle nor able to support you in one. Most of them only give you quests or are shop owners (some both).
“Warren (ワック Wack) is a boy who stays at Ariela's Tavern. He is sick when Dagran's Mercenaries...Warren
“Jeffery is a commentator for the Arena alongside Franklin. He is replaced in Arena season 3 by...Jeffery
“Franklin is a male character from The Last Story, and one of the commentators in the Arena...Franklin