Chapman’s new lack of privacy is accompanied by a serious case of rape anxiety, which gets worse when word leaks about her lesbian past. (Her current fiancé is a male writer, played by Jason Biggs, but she quickly attracts the amorous attention of an inmate named Crazy Eyes.) Other worries include the risk of fungal infection and the entwined privileges and dangers of being well educated and white, a situation that’s openly and frequently addressed but not explored in any significant way, at least in the early episodes.

None of these threats ever seem particularly menacing. “Orange” may be a roughly hourlong show, but it has the soul of a sitcom or a teen drama — it’s more “Gossip Girl” than “Oz” — and situations tend to resolve themselves through slightly over-the-top humor and an increasingly prevalent sentimentality.

As with the excellent first season of “Weeds,” the humor in “Orange” is often sharp, particularly when it focuses on Chapman’s self-absorption and neuroses. Bidding her amazingly patient fiancé farewell before entering the prison, she tells him: “Please send that check immediately. I love you. Please keep my Web site updated. I love you so much.” A scene of the fiancé masturbating is an homage to Mr. Biggs’s breakout role in “American Pie.”

When it’s not being funny, though, “Orange” (a reference to the color of the jump suits new inmates wear) can seem inconsequential. Chapman’s cringing process through the penal system is always amusing, but the other inmates’ stories — and there are a lot of them — tend toward big-house clichés, right down to lines like “You need to man up” and “Hope is a dangerous thing.”

The show’s structure, in which constant short flashbacks explain, very gradually, how the women came to be in prison, contributes to a sense that not a whole lot is going on, despite the multiplicity of featured characters. And the size of the ensemble means that characters we become attached to, like Mr. Biggs’s Larry Bloom, will disappear for long stretches.