When This Is Us arrived, it was an anomaly. Now it's a trend.

Well, maybe a mini-trend. Or a micro-trend. At least, it's made an impact.

"I feel really lucky," producer Joan Rater told the Television Critics Association in January. "We get to tell these stories, thanks to shows like This Is Us."

Her new show, Council of Dads, has a direct link: This Is Us has its season-finale at 9 p.m. ET, Tuesday, on NBC, and Council follows at 10:01 p.m. ET, aiming for a similar audience.

"They were the prow of the ship," said Michael O'Neill, one of the Council co-stars, "and I'm very happy to go into harbor behind them. But that appetite has always been there."

Maybe viewers did have an appetite for warm human drama, but networks doubted it. There used to be several such shows, often set in the past (The Waltons, Little House on the Prairie), but they vanished.

When eyeing the fall schedules for 2016, CBS' Kelly Kahl was optimistic that his courtroom show, Bull, would prevail. NBC's show, he'd heard, was quite "soft."

That was This Is Us, which had none of the usual trappings of network dramas – no cops, crooks or courts, no doctors, firefighters, or soldiers. It was about day-to-day life; TV didn't usually work that way.

Roberto Aguirre-Sacasa found that out that same year when he began pitching what he thought would be "a slice-of-life, coming-of-age" story based on the sweet-spirited Archie comic books. Greg Berlanti, a top producer, liked the idea, he said – "but Greg said, 'You're going to need a dead body.'"

Aguirre-Sacasa doubted that and kept pitching the idea unsuccessfully. "Seven months (later), I was sort of like, 'We need a dead body.'"

The show (Riverdale) debuted in 2017 on the CW network with one dead body and added more. Soon, Jughead was a gang leader, and Archie was a cage-fighter in prison.

The broadcast networks were like that – avoiding dramas that were merely about human emotion unless it was the hyper emotion of the soap-opera genre.

Then This Is Us found an audience.

In its first season, it was No. 6 in the Nielsen ratings, just a notch behind Bull. It peaked in its second year at No. 4, then was back at No. 6 its third season (with Bull at 13).

Ratings have declined again this season, but This Is Us remains No. 1 among scripted shows in the age group (18-49) that advertisers prefer. That's enough to spark a mini-trend.

CBS' God Friended Me found quick success; ABC's A Million Little Things (which ends its second season Thursday) did adequately. NBC failed with The Village, but succeeded by piling lots of This Is Us style drama into a hospital show, New Amsterdam. Now it has Council of Dads.

The idea began in 2008 when Bruce Feiler was diagnosed with a rare form of cancer. Feiler was already a famous writer; his 2001 Walking the Bible had been a bestseller.

But at 43, he was facing the possibility of early death. He asked six friends to watch his two young daughters if he died; his 2010 Council of Dads became another bestseller.

Rater and her husband (both Grey's Anatomy veterans) took it from there. "Joan and I kind of took this idea from Bruce Feiler's book and grafted our own family onto it," Tony Phelan said. "We have our daughter, Sally, we adopted from China. And our son, Tom, is transgender."

They trimmed the "council" in half, expanded the number of kids, and made another key change that viewers will see in the first hour. But they filmed it near Feiler's hometown of Savannah.

And they kept the book's attitude. "The modern family (is) not about blood," Clive Standen, who plays one of the "dads," said. "It's about love and the people who show up every day."