Are any of them available in the US?
Well, Anpanman and Doraemon seem to be about as popular and famous as Mickey Mouse and Snoopy are in the US. You see them everywhere and everyone knows them. As far as I know neither show was ever exported to the West.
Anpanman is a superhero made of anpan (a kind of roll with bean paste inside; imagine “Doughnut Man”). He is the creation of the kindly Uncle Jam, and has various food-themed friends. They fight germ villains and rescue people. This often involves needy, hungry people eating part or all of Anpanman’s head. (I’m unclear as to whether the anpan head has magical properties or if it just satisfies their hunger.) Anpanman’s head also sometimes dissolves in the rain or gets damaged in other ways. But this is no problem for Anpanman, as Uncle Jam can always bake him a new head.
This whole head-eating thing seems pretty weird even to the Japanese, but the show has been on forever and is targeted at little kids anyway so no one really questions it.
Doraemon was a comic book first, and strikes me as being pretty similar to Calvin and Hobbes. It’s about a young boy named Nobita and his adventures with the title character, a cat robot. Nobita is kind of a loser, so his descendants sent the robot back in time from the future to help him. Doraemon has a 4-D pocket that he can pull all kinds of sci-fi gadgets from, but these often cause more trouble than they’re worth.