# Hunter Invitation
Sometime in the game a quest will become available in the Ailily guild that involves giving Arche a Mabo Curry. It does not matter if you make it or get one as a reward, but you will most likely not find one until late in the game as it is semi-rare. When you give it to her, she will say that it is going to be for Chester. Later, you will get a scene in the Ailily guild that involves Arche giving the curry to Chester. Chester will get depressed and ask Arche to leave him alone for awhile. After more time, you will see a scene in the Ailily plaza that involves you cheering up Chester. Tell him that "Arche didn't mean to offend you", and he will say that he knows and will thank you for cheering him up. Before he leaves, he will give you the Hunter Invitation, which allows you to change your class to Hunter.
# Magic Knight Invitation
Once you are about level 40, check with Raine in the Ailily guild until you find a quest from Kratos requesting you to battle him. He is not easy to defeat, with close to 30,000 HP and a near instant heal that he uses whenever his health gets low. Once you defeat him, he will say he is amazed you surpassed him and will give you the Magic Knight Invitation. This allows you to change your class to Magic Knight. You will need 1,000 grade before you can change to this class.
# Ninja Invitation
You first need to have a level 30+ fighter. After reaching level 30+, keep doing quests in Gavada to build up fame until the "Test your skills with Senel" quest is available. Take this quest, and defeat Senel. Note: It is nearly impossible to defeat Senel at level 30. Train your fighter to level 35 or higher before fighting Senel. After defeating Senel, report back to him. You will be rewarded for the quest. Afterwards, talk to him again. Senel will give you the Ninja Invitation. This allows you to change your class to Ninja. Note: It takes 1000 grade points to change to Ninja.