In the fall, I am going to start a new AD&D campaign but using Oriental adventures. I haven't decided what setting I am going to use or if I'm going to make something up. EDIT I will be using the country descriptions from OA 1st edition for the realm of Kara-Tur, but using a map of Japan.
Spirit folk- Spirit folk are part human, but one of their parents was a spirit. They have different special abilities depending on the spirit type but they can be affected by both people and spirit targeting spells. Can be any class.
Hengeyokai- Shapeshifters who can appear human, part human-part animal or animal form with different powers in each form. Can be kensai, wu-jen, bushi, shukenja, thieves.
Wu-jen- Asian wizards, but more spiritual and having a chosen elemental focus (fire, earth, etc)
Shukenja- Asian priests, summoning spirits rather than channeling the power of a god
Samurai- noble warriors
Bushi- soldiers and common fighters
Kensai- weapon masters, devoted to the mastery of a single weapon
Monks- martial arts masters who combine mystical powers with deadly open hand fighting and weapon skills
Tattooed Monks- Monks whose powers come from enchanted tattoos
Thieves- not ninjas, ninjas are assassin NPCs unless someone comes up with a great backstory. Oriental thieves are independents, trained by their master, as opposed to organized gangs like western thieves' guilds