Arzela is a Tanua who works as The Mercenary's navigator. She originally work for a transportation company as a navigator for one of there vessels, however after an accident involving the ship (which she was blamed for but was not her fault) Arzela quit her job.

After several failed attempts to get another job because of being shy, she meet Rosie The Mercenary's captain in a bar and asked if she could join the crew after overhearing Rosie mentioning she needed a navigator for her ship.