Aha, I assumed you’d been murdered outside Union Station. One less death on my conscience!
1. Is seafood okay with your gf? Coni Seafood in Inglewood is known for pescado zarandeado and smoked marlin tacos, but many other dishes are top notch, too. And Guerilla Tacos is extremely veg-friendly. (Though possibly closed until the new year? Their webpage is confusing on this point.)
2. I’m not that familiar with Little Tokyo, but definitely check out Marugame Monzo for fresh-made udon. The uni udon is their signature dish, but you should also try a cold dish to really appreciate the texture of the noodles. Budget-friendly, for sure. Elsewhere, your best bet for budget Japanese may be lunch, when many places have specials/set menus. Aburiya Raku is the best I’ve had here, but I can also wholeheartedly recommend Sushi Tsujita and Sushi Sasabune.
3. When I’m in Pasadena (as I am now, in fact), I usually drive 20 minutes to SGV for some of the best Chinese food in the U.S. (also Vietnamese, Burmese, etc.) But in Pasadena proper, I’m a big fan of Euro Pane Bakery for great pastry and the best egg-salad sandwich I’ve ever had (two locations, the one farther west is a bit fancier inside). Prices are very reasonable, especially for the quality. I also hear that Osawa is very good, but haven’t tried it yet. Finally, consider going up to Altadena for great gelato at Bulgarini.
Edit: Just reconfirmed yesterday what an insanely good deal Sushi Tsujita's chirashi lunch special is. $18 gets you a nice-sized box chock full of amazing quality seafood over seasoned rice, plus soup (not always miso, although that’s great there, too). They only have 15 of these per day, but in my experience you'll have no problem snagging one if you get there before noon; yesterday, I bet they still had them around 1. The other lunch specials are great too, just not quite an astounding a value. Quality is top notch across the board.
Open New Year's Eve and Day, then closed for vacation 1/2-1/4.
Edit #2: Tsujita Killer Noodle is awesome. Highly recommend the “Tokyo style” tantanmen — either with soup or without. I eat a lot of spicy food and 5/5 on heat/numbing was more than sufficiently hot for me; might even go lower next time.