I'm not Taiwanese, so I don't know for sure if it's really authentic, but it seems to be as far as I can tell! It's not fancy or high class, but it's a clean *very clean* little cafe with Taiwanese/Japanese style bento featuring various entrees. I suggest the stewed pork, which is their specialty. The pork chop is popular as well, but some may find it to be too greasy. They also have boba milk tea and green bean soup to complement your meal for only one dollar!
By the way, this is a review for the Milpitas Square location, not San Jose, since I have never been to that one. For some reason, the Milpitas shop is not listed on this site.