How do you increase Carrying Copacity in Valhalla Knights eldar saga

You will raise your capacity by one point when you raise your job (mage, fighter, priest, thief, etc.) by 5 levels.

NOTE When you change jobs, you will not keep your capacity level, as it will change depending on you JOB level.

Ex: If you are level 10 mage and level 15 warrior, and your starting capacity is 10, you will have 12 capacity as a mage and 13 as a warrior.