Keep your friends close and your enemies closer.

At least, that's the rule Milo Ventimiglia and Catherine Haena Kim's characters in The Company You Keep certainly live by. And while the show itself is full of sexy moments, the stars' favorite things about one another are a bit more wholesome.

"I'm always impressed with Catherine's intellect, just her desire to know things, understand things," Milo exclusively told E! News' Justin Sylvester and Adrienne Bailon-Houghton March 15. "Not just surface level, but at a depth."

Catherine echoed her co-star, adding, "He's just as gracious and grounded in life as he appears when you see him on a show like this. It's really refreshing, it's nice to see and it's nice to work with."

Milo and Catherine star as star-crossed lovers Charlie and Emma in the steamy ABC drama about a con man and a CIA agent who must juggle their unconventional relationship with their career aspirations as they find themselves on opposites sides of the law.

The actor also explained how he picked this show to be his follow-up after six seasons of This Is Us. 

"It had all the makings of a good time, opportunity, as well as story," Milo said of developing the series with friend Jon M. Chu and creator Julia Cohen. "First and foremost, Hollywood forgets we're here to entertain. We want things to be fun."

He continued, "It had Charlie, the role of course for me to play and step into—but also Catherine and other talented actresses to come through and have fun with us."

Though the cast is new to Milo, he revealed he's pretty familiar with the people behind the scenes.

"I brought the crew from This Is Us to The Company You Keep—as many as I could," the Gilmore Girls alum revealed. "We're filming in the same studio. There's that regularity, you know everybody, you see everybody on a daily basis."

But as a longtime fan of the former Heroes star, which of Milo's iconic roles is actually Catherine's favorite?

"I think I'm Art of Racing in the Rain Milo," she shared. "He's like the renaissance man: he races cars, he can ride a bike. When I was doing research to be a CIA officer, he was like, 'Do you want to talk to somebody?' I'm sorry, why do you know people to talk to?"

See their connection in action in The Company You Keep, Sundays on ABC. Plus, check out more can't-miss interviews on E! News, weeknights at 11 p.m. EST, only on E!.