He looks more like a Swedish tennis star than a former yeshiva boy, but novelist Joshua Braff is living proof it takes one to know one.

Braff drew on his days as a pre-teen yeshiva student to write “The Unthinkable Thoughts of Jacob Green,” a riotous coming-of-age novel set in his native New Jersey.

Braff’s brother happens to be Zack Braff, star of the sit-com “Scrubs” and writer/ director/star of the recently released screen comedy “Garden City,” which earned glowing reviews.

But Joshua Braff, 36, has been garnering raves of his own thanks to his wickedly satirical take on East Coast Jewish life circa 1980. He will meet and greet local book lovers when he appears at the Jewish Book Fair at the Jewish Community Center of San Francisco on Sunday, Nov. 7.

“This is my first published book,” he says, “So, you go with what you know. I did draw from truth, but it is not my family. These characters became hybrids of people I’ve observed and known.”

In Braff’s novel, a sympathetic young teen struggles with an abusive father, a rebellious older brother and a sexual awakening that’s more pain than pleasure.

All the while, young Jacob Green is forced by his father to be the model Hebrew School student. Braff writes in the first person, present tense, allowing readers to crawl into the mind of Jacob. It’s alternately hilarious and tragic.

With so many detailed Jewish references — everything from the wrapping of tefillin and transliterated Jewish prayers to the subtleties of writing bar mitzvah present thank-you notes — Braff might have gone over the heads of his non-Jewish readers. But so far, he says, readers of all stripes respond to the universal nature of the story.

“The Jewish reaction to the book has been one of recognizing people like that in their own families,” notes Braff. “A few were taken back by some of it, and some thought it was anti-Semitic.”

It’s true, Braff paints some characters, particular the narcissistic father Abram Green, in an unflattering light. But the author affirms his own high regard for Judaism.

“I’m proud of being a Jew,” says Braff, “and the respect I have is legitimate. I visited Israel when I was 22 and had an amazing experience. It was the first time I had Judaism offered to me on my own terms.”

That hadn’t been the case during his boyhood days at the local Solomon Schechter School. One episode in the novel, in which a mean Hebrew teacher lines up his male charges for tzitzit inspection, is based on personal experience.

“Some of the rabbis didn’t like kids,” he recalls. “They smoked cigarettes and drank coffee, and if you forgot your tzitzit, you would be punished. Your parents were always notified when you fumbled a ritual.”

A Harvard graduate, Braff moved to California to pursue his creative writing education. He’s been living in the Bay Area for the past 10 years.

“I wear my Giants hat with pride,” says the father of two. “I spend a lot of time in the cafes near Haight Street. I appreciate the people watching there. There’s a liberal mentality in the Bay Area I find essential in my life.”

He’ll have to give it up for a time, as Braff is in the midst of an extensive publicity tour promoting his book, a novel experience indeed. “It’s a little bizarre and surreal at times,” he says, “but the more readings I do, the more confidence I have.

And like any first-time novelist, Braff has high hopes for his book and for his readers. “I want it to be a really good ride. I want people to be touched and to laugh, to connect it to their own lives and memories. That makes for books that last, that people talk about.”

Joshua Braff will appear at the Jewish Book Fair, 1:50 p.m., Sunday, Nov. 7, at the JCCSF, 3200 California St.

“The Unthinkable Thoughts of Jacob Green” by Joshua Braff ($23.95, Algonquin Books, 272 pages)