More importantly, I don't think the distinction exists in Japanese.
Well... nobility in Japan used to derive from a combination of 'degrees of perceived blood relation to Emperor Jimmu (legendary first emperor, grandson of the Sun Goddess)' and 'delicacy of character' - you know, ancestry and talent for the arty hipster crap that the Heian court adored to bits. Usually they're the ones with the actual titles and such, but after the Taira vs Minamoto feud of the twelfth century, that's about all they had.
As the samurai class rose in prominence, that idea of 'nobility through divine ancestry and patronage of the arts' never fully went away, but you'd be hard-pressed to say the less-divine and generally less-cultured samurai
didn't count as noble to one extent or another under a Western definition; there's a reason missionaries referred to the shogun as the Emperor of Japan and the actual emperor as the Pope of Japan. High-ranked military families owned a lot of the land, they invested capital in the nation's maintenance and in the maintenance of their own vast wealth, they raised their daughters to be diplomats and accountants, they raised their sons to be strategists and administrators, and when they murdered some peasant it was more of a social scandal than a legal matter. Hell, the Tokugawa even instituted a much-less-ridiculous version of the Versailles system in order to keep the samurai in line (basically every nobleman had to house his wife and family in the capital, and he could only go home to administer his lands in person in alternating years).
During the belated Industrial Revolution that the Meiji Restoration kicked off, it became (after much outrage) socially acceptable for businessmen to become ludicrously wealthy, which several of them promptly did. And in the post-WWII era, after the US military made a point of scouring out most of the more authentic or alarming (to them) bits of samurai culture, this Benihana Bourgeoisie is where one turns to to find the source of the 'magnificent princes' of anime fame; high-strung young men whose families, in many cases lacking a samurai heritage or divine antecedents, have striven to make their children more noble than the nobles - often by amalgamating Japanese ideals of nobility with Western ones. There are still a few families of noble descent in Japan today, it's just that most of them had to drop down to the 'oodles of money but no land and titles' class, or even just plain middle class, over time, in order to survive.
So... that kind of got away from me. ._.; Um, I think my point was that in my view, you're more likely to see characters you could classify as gentry in a story set post- or during the Taisho Period, and you're more likely to see what Westerners would consider nobles in stories set during and before the Edo Period.
Occasionally you do get to see gentry in stuff specifically about the Meiji Restoration - I'd classify most of the main cast of Hakuouki as gentry; Hijikata is a self-taught swordsman from an undefined background, but Saito and especially Okita are from eminently respectable families.
Edit: How the hell did I think Jimmu's name was Temmu? Ugh, fixed.
