Originally developed for Showtime, “Crazy Ex-Girlfriend’s” premium-TV origins are apparent in its approach to a lead character whose behavior certainly fits the adjective. Yet as played by Rachel Bloom, she’s a surprisingly endearing figure — wildly impulsive, unhappy and, thankfully, prone to bursting out into musical spectacular-type song. Once again, CW, with its targeted approach to introducing new shows, has delivered one of the fall’s most promising hours, with a series that might not be worth schlepping all the way to West Covina over (unless you’re Crazy), but which does warrant happily plopping your fanny down on the couch.

Bloom’s Rebecca Bunch is introduced at age 16, as her boyfriend from summer camp, Josh (Vincent Rodriguez III), says goodbye and rather unceremoniously breaks up with her. Flash forward a decade, and Rebecca is on the verge of being named partner at a big New York law firm, seemingly at the top of her game, when during one of her many sleepless nights she sees a commercial that asks, “When was the last time you were truly happy?”

A chance encounter with Josh on the streets of Manhattan drives home when that moment was. Yet as luck would have it, he’s moving back to West Covina, Calif., a sleepy little berg described by pretty much everyone as being “two hours from the beach, four in traffic.”

The next thing you know, Rebecca has chucked it all, leaving the Big Apple and heading West — a move that nobody seems to understand. Certainly not her co-workers at the new firm she joins, who, initially led by Paula (Donna Lynne Champlin), are suspicious why she would land there given her resume; or the helpful bartender (Santino Fontana, the voice of Hans in “Frozen”) she meets, who, as an acquaintance of Josh’s, might be of use.

There are all kinds of ways “Crazy Ex-Girlfriend” could go off the rails, especially if Rebecca’s “I am not crazy” protestations begin to sound more hollow than amusing. After all, her obsession with and social-media stalking of Josh is being played for laughs, when it could just as easily be flipped into “Fatal Attraction.”

As presented in the pilot, though — written by Bloom and Aline Brosh McKenna, and directed by Marc Webb – the series is infused with a kind of infectious energy, starting with the production numbers, that makes it an ideal companion for “Jane the Virgin.” The main difference would be that while Jane is the level-headed presence surrounded by lunacy, here Rebecca’s the driver of the crazy train.

Perhaps foremost, the series almost immediately establishes a distinctive voice, and sets up Bloom as a talent to be reckoned with. And while that might not spell happily ever after for “Crazy Ex-Girlfriend,” if the premiere’s charms can be sustained, this could be one of those shows that a hardy core of viewers will want to keep seeing for a very long time.

TV Review: ‘Crazy Ex-Girlfriend’

(Series; CW, Mon. Oct. 12, 8 p.m.)

  • Production: Filmed in Los Angeles by Sunnyside Entertainment and Webbterfuge in association with Warner Bros Television and CBS Television Studios.
  • Crew: Executive producers, Rachel Bloom, Aline Brosh McKenna, Marc Webb; producer, Sarah Caplan; director, Webb; writers, Bloom, Brosh McKenna; camera, Jonathan Sela; production designers, Laura Fox, Stephen McCabe; editor, Kabir Akhtar; original songs written by Bloom, Jack Dolgen, Jerome Kurtenbach; casting, Felicia Fasano, Bernard Telsey. <strong>60 MIN.</strong>
  • Cast: Rachel Bloom, Santino Fontana, Donna Lynne Champlin, Vincent Rodriguez III, Pete Gardner, Vella Lovell