So long as you don’t go expecting too much, you should find Gary Winick’s sharp, tidy little walk in “Graduate” territory an amusing addition to the coming-of-age genre, much more sophisticated and literate than such pictures usually are. “Tadpole” is the curious nickname of the central character, Oscar Grubman (Aaron Stanford), a gifted but socially stilted prep school student returning to New York City to spend Thanksgiving vacation with his father Stanley (John Ritter), a Columbia history professor, and his comely stepmother Eve (Sigourney Weaver), a medical researcher. Oscar’s remarkable for a fifteen-year old–his mastery of French is awesome, and Voltaire seems to be his favorite author–but what’s even more peculiar is that he shuns girls his own age, however pretty they might be; he’s smitten, as he eventually confides to school chum Charlie (Robert Iler), with Eve, and it’s his intention to make his feelings known to her during his stay. Needless to say, his plans go awry; most notably, he stumbles into a tryst with his stepmother’s best friend Diane (Bebe Neuwirth), a masseuse who has no qualms about romancing the boy, and must keep his father from learning the truth while finding the right moment to declare his love to Eve.

Oscar’s interest in things Gallic seems absolutely right in view of the rather racy sexual implications at work here–some viewers might find the very idea of relations between characters of such disparate ages too unsavory to stomach–but it’s the saving grace of “Tadpole” that most everything is handled with a relatively light touch and canny comedic timing. It’s rare, for instance, to find the genteel, tweedy pomposity of academia satirized with as much insight as here; and there’s a naturalness to the interplay between Oscar and Charlie that’s refreshing when most teens in movies are portrayed in the crudest strokes. The high point comes during a restaurant scene staged, quite appropriately, like the climax of a French drawing-room comedy. Oscar is showing off his linguistic dexterity while trying desperately to prevent Diane from revealing their dalliance to Stanley and Eve. Meanwhile Stanley bumps into the sweet classmate with whom Oscar has falsely claimed to be spending time in order to hide the truth about where he was, and an increasingly tipsy Diane loses her self-control, much to Oscar’s dismay. It’s a sequence that demands delicate ensemble control not to go off the rails, and the players and Winick find exactly the proper tone. The bittersweet conclusion, too, is refreshingly low-key and sane. Not all of the picture maintains the same high standard, but major missteps–like a clumsy gag about Oscar’s gluing phony sideburns onto his face to impress Eve–are refreshingly rare, and the plot elements that could have gotten a bit gamey remain fundamentally inoffensive.

The cast is a major reason behind this success. Though he looks rather older than fifteen, Stanford makes Oscar agreeably obsessive without turning him into a caricature, and Ritter proves, with his quiet, understated befuddlement, that he’s become a character actor of considerable distinction. (That will probably come as a revelation to many viewers, but those who saw him in Henry Bromell’s “Panic” won’t be surprised.) Weaver shows grace and vulnerability as the unwitting object of young Oscar’s attention, though she can’t entirely conceal the discomfort of the role. The sole fly in the thespian ointment is Neuwirth, who pushes too hard as Diane; a little less stridency would have been the wiser choice.

“Tadpole” is quite clearly a modestly-budgeted film. Shot on digital video, it’s visually not terribly attractive, often grainy and overlit. Its raggedness has a certain naive charm, but it would probably be a chore to watch much more than the 78 minutes to which it’s been crisply edited by Susan Littenberg. As it is, the brevity assures both that the wit doesn’t flag and that the primitive camerawork doesn’t cause excessive eyestrain. “Tadpole” may not be a comedic big fish, but it’s an amusing little catch.