Writer-director Michihito Fujii puts the “sag” back in “saga” with his soapy, melodramatic mob movie “A Family,” originally-titled “Yakuza and the Family.”

It has plenty of the sorts of characters and plot elements you expect when you hear a film described as a Yakuza movie. Lots of Japanese mobsters, laughing too loud, bellowing threats even louder — whole torso tattoos, knives and clubs and the occasional firearm wielded without pity, turf wars with bloody violence, “old men” being told “Your time is finished.”

These are tropes of mob movies, from Sicily to the Jersey Shore, Odessa to Little Odessa to Osaka.

But here, they’re mostly in the first act. “A Family” then takes a shot at showing the trap of “the life,” the price of this loyalty you give to someone, a boss, who may or may not be a blood relative. The picture has little momentum even as its forward motion takes us through the rise and fall of a young gangster, born into “the business” even if he wasn’t born into this particular family.

Gô Ayano is “Lil Ken,” Kenji Yamamoto, and we meet him after his father’s death. “Lil Ken” is his most flattering nickname. “Yamamoto’s brat” is another.

He’s a blond mop-topped motor-scooter punk when we meet him in 1999, a fashion statement in white jeans, shirt and North Face jacket. He’s got boys he runs around with, but the mob life isn’t for him, rejecting his father’s business, as it were.

An impulse robbery of a low-level drug dealer changes that. A moment of bravado, interrupting a hit on mob boss Shibasaki (veteran character actor Hirosihi Tachi, who was Admiral Yamamoto in “The Great War of Archimedes”), cements that change.

When the rival Kyoyo-tai clan takes out him and his boys for stealing their drugs, covering Lil Ken and his all-white ensemble in his own blood, a business card from Shibasaki is what saves his life.

“A Family” follows Lil Ken from his “drink from the family cup” initiation, into mob intrigues some years later and finally takes us to 2019, where he’s now an ex-con, trying to rejoin a society that won’t let yakuza have legit jobs, rent apartments or sign up for bank accounts.

There’s a woman, a “hostess girl” (Machiko Ono) from one of the gang’s clubs, and a relationship that starts with bullying and somehow softens into 20 Questions — “Why do yakuza wear sunglasses at night?”

And there’s a kid, warned as a toddler so that he won’t “turn out like us,” but who (Hayato Isomura) pops back into Lil Ken’s life like a 2019 version of himself (Tommy jacket instead of NorthFace).

The acting is quite good, with Ayano (of “The Promised Land” and the recent “Humunculous”) a charismatic lead. The mob brawls and chases early on are visceral enough to pull you in.

But Ono lets the air out of the balloon of even the action sequences entirely too quickly. The “family” material is less interesting, the “relationship” perfunctory and even acts of vengeance seem rushed so that we can get back to the boring stuff.

Which unfortunately eats up most of the 136 minute run time of “A Family.”

MPA Rating: TV-MA, graphic violence, sex, nudity, smoking

Cast: Gô Ayano, Hiroshi Tachi, Machiko Ono, Yukiya Kitamura and Kosuke Toyohara

Credits: Scripted and directed by Michihito Fujii. A Netflix release.

Running time: 2:16