I guess for me, they're adults in a fantasy world though. Like, Jormungand has nearly an all adult cast as well, but very few people are dealing with the massacre of their military unit or ex-mafia guys or whatever the backstory is for the other characters.
The only anime that I can think of about adults in the real world are all noitaminA shows. (Yes, I count Ristorante Paradiso in that group, duckroll
)
Oh, and I suppose those BL shows centered around the Sekai-ichii Hatsukoi franchise. But they're not real human beings either. lol
It's weird. I don't really like Modern Family any more, but if there was an anime that tried to do the exact same thing, it'd probably be my favourite thing ever. lol
Like, what if an older Japanese divorcee married a Filipino woman and had to remember how to be a father again because she was a single mother? What would his kids think about the marriage? What if one of his kids were gay? I'd be happy if an anime even gestured at doing something a bit more socially aware even off handedly.
(Of course, the answer is that I should watch more jdrama because that's where all the adult stuff goes. But I really don't want to do that.
)