There are quite a few different options for characters, so you'll be able to create a relatively unique character. You'll choose your school, Dragon or Owl. Each school will have their own unique quests to do and characters that they interact with, so I recommend you make a character (you're allowed up to 4) in each just to see everything. You can choose your characters gender, height, face shape, hair color, all of which let you create a very unique character. I do wish you could have a bit more though so you could create a character for each class and specialty.
There are three classes of characters: Gun Circle, Magic Circle, and Fight Circle. Gun Circle are the long range attackers, Magic Circle are magic users, and Fight Circle are melee fighters. Once you reach level 10, you'll pass on to second grade, where you choose a specialty. Each class has two different specialties, each with different drawbacks and benefits. Overall, I've enjoyed the Gun Circle the most and the Fight Circle the least, which is actually opposite of normal for me. I tend to prefer a melee character, but the melee characters are a bit underpowered and I found that I went broke on healing potions and took longer to complete quests with them.