There aren't a lot, and most of them are older. A few that come to mind are Delicious in Dungeon, Ghost in the Shell, Odd Taxi, Baccano!, and Redline. Three more with one child in a cast of adults (and for all of them, they aren't standard cutesy anime children) are Cowboy Bebop, Golden Kamuy, and Vinland Saga.
One Punch Man technically counts except for Child Emperor (who barely shows up) but Tatsumaki is probably over the line for sexualization of a character who looks like a child.
Less popular but still good: Planetes, Tatami Galaxy, Shirobako, Legend of the Galactic Heroes, Patlabor, Black Lagoon, Welcome to the NHK.
Less popular and not great: Akudama Drive, Way of the Househusband.
I mean, it feels strange to me to say that there aren't a lot. I would sooner say that there are fewer rather than that there are strictly few. Just looking at the top 100 anime on Anilist, I'd say that there are actually quite a lot that seem to have primarily adult casts, although I suppose appearances and plot descriptions can be deceiving — as can outright searching by the tag "primarily adult cast".
And then even of anime and manga that normally depict teenagers, there are a handful which have movies or spinoffs or whatever that depict the characters as adults. The YuruCamp Movie from 2022 stands out, that was a great movie. And Lucky Star has now an ongoing spinoff manga called Konata 30 which depicts all the characters in their 30s, that started last year.
There aren't a lot, and most of them are older. A few that come to mind are Delicious in Dungeon, Ghost in the Shell, Odd Taxi, Baccano!, and Redline. Three more with one child in a cast of adults (and for all of them, they aren't standard cutesy anime children) are Cowboy Bebop, Golden Kamuy, and Vinland Saga.
One Punch Man technically counts except for Child Emperor (who barely shows up) but Tatsumaki is probably over the line for sexualization of a character who looks like a child.
Less popular but still good: Planetes, Tatami Galaxy, Shirobako, Legend of the Galactic Heroes, Patlabor, Black Lagoon, Welcome to the NHK.
Less popular and not great: Akudama Drive, Way of the Househusband.
I mean, it feels strange to me to say that there aren't a lot. I would sooner say that there are fewer rather than that there are strictly few. Just looking at the top 100 anime on Anilist, I'd say that there are actually quite a lot that seem to have primarily adult casts, although I suppose appearances and plot descriptions can be deceiving — as can outright searching by the tag "primarily adult cast".
And then even of anime and manga that normally depict teenagers, there are a handful which have movies or spinoffs or whatever that depict the characters as adults. The YuruCamp Movie from 2022 stands out, that was a great movie. And Lucky Star has now an ongoing spinoff manga called Konata 30 which depicts all the characters in their 30s, that started last year.