As already pointed out, you should better consider how to treat multi-classed characters, especially someone with prestige class.
But anyway, as a Japanese myself, I want to add some comments on Japanese-themed titles.
>Samurai
>1st-5th Ronin
>6th-10th Bushi
>11th-15th Shogun
>16th-20th Samurai Lord
The word "Ronin" means, a samurai without someone (or a house) to serve. A samurai become ronin when they lost their lord (or the entire house of the lord itself), or dismissed. And actually, there is a prestige class called Ronin in Complete Warrior (though not exactly reflecting Japanese word Ronin).
And "Bushi" and "Samurai" used almost in the same meaning. Though precisely, Bushi is more like "warrior" and "Samurai" is more like "the one who serves".
"Shogun" is short for "Seii-Tai-Shogun". That is the title of the supreme commander of all the samurais. So, it should be left for the highest ranked one. Historically, there could be only one Shogun at a time. And only Japanese Emperor could give that title. That title will never go under "Samurai Lord" or something.
If you want to reflect the feudalism, my suggestion is
Samurai
1st-5th Bushi
6th-10th Shomyo (Landed Lord of smaller area)
11th-15th Daimyo (Landed Lord of larger area)
16th-20th Shogun (the Supreme Commander of All the Samurais)
>Wu Jen
>1st-5th Eunuch
>6th-10th Youjutsu
>11th-15th Kisai
>16th-20th Sangun
Wu-Jen is Chinese medium/wizard. All I can say is that you should better use chinese titles instead of Japanese ones such as Youjutsu or Kisai. I can't understand what does Sangun mean but that sounds more like Japanese word than to be a Chinese word.
Maybe you should take words from Cantonese as the word Wu-Jen is from Cantonese and not from Mandarin (Putonghua). And I don't think all the Wu-Jens to be Eunuch.
Or you can just use the same title for Wizard class.
>Shugenja
>1st-5th Shinto
>6th-10th Seijin
>11th-15th Sensei
>16th-20th Shounin
Shugenja is the practitioners of Shugendo. And Shugendo is a religion/mystic practice based on ancient Japanese mountain-worshipping and influenced by Shintoism, Buddhism, Taoism & Onmyo-do.
So, using the word "Shinto" is inappropriate.
"Seijin", is usually used as the translation for the English word "Saint" (or European equivalent of that word). Most japanese people will imagine Christian Saints from that word.
The word "Sensei" means "Teacher" or "Mentor". But actually, that words sounds modern.
The word "Shounin" is usually used for high-ranked Buddhist priest. Though, Shugendo has a strong tie with Japanese Buddhism and some famous Buddhist priests in the history are also known to be practitioners of Shugendo.
Different sects of Shugendo are using different sets of titles. But those are not so popularly known and for non-practitioners of Shugendo, all of them are just Shugenja, or Gyoja (who commit gyo=practice). Or Yamabushi, the one who lives in mountains. Even the legendary person whom widely considered to be the founder of Shugendo, was called En-No-Gyoja. That simply means "Gyoja En".
So it is very difficult to suggest appropriate titles for this class. Maybe you would better make up English titles instead of using Japanese words.
>Ninja
>1st-5th Yakuza
>6th-10th Goju
>11th-15th Nightblade
>16th-20th Onryou (Ghost)
Well, first of all, Ninja is not meant to be someone with official titles. They are undercover agents and of underground world.
The only appropriate titles I can think of are Genin (lower rank Ninja) and Jonin (higher rank Ninja). But it is basically said that Genin were commoner ninjas and Jonin are ninja of Samurai class (not the D&D Samurai class but historical social class). And usually, a Ninja whom born as a Genin never became Jonin.
So, maybe giving made-up English titles should be much appropriate. As Ninja class is not only restricted in setting with Oriental tastes (You can find Dragon Spawn Ninja, Drow Ninja, etc., in MM IV or other supplements).
Using the word "Yakuza" is clearly inappropriate. The word is used for the members of Japanese crime syndicate and also a rather modern word.
"Goju" sounds like Japanese. Maybe you took that ward from a martial art style "Goju-Ryu" but that style is basically a variation of Karate. As Karate is not at all related to Ninja, that word should be inappropriate.
