I checked out two Asian groceries in Guadalajara this morning. I think they're the only two around, although they each have at least two stores. One just opened a store right by the other so it's easy to go to both to see what works for you.
The first is simply called Asian Market and is on 2154 Mexico. The cross street is Alfredo R. Plascencia. It's quite a bit larger than the other and had a wider variety of food. There wasn't any fresh produce. I was able to get some rice noodles and gochujang which I hadn't seen anywhere else. They had fish sauce, rice vinegar, soybean paste, etc. but I'd already been able to find those at a store in my neighborhood and they weren't any cheaper at the big store, so I don't think I'll need to go there often. The rice noodles were fairly expensive, so I'll probably end up shipping them here since they're lightweight and we like them a lot. There's supposed to be another branch of this store on Av. Americas just south of the intersection with Lopez Mateos.
The other store is Toyo and it's just east on Mexico on Manuel M. Dieguez. It's less diverse with more Japanese food. Sushi is really popular here so that makes sense that Japanese ingredients would have gotten here first. I think they have several branches around town. I didn't get anything here because the store in my neighborhood has what I need that Toyo carries, or Asian Market has it.
I think Asian Market is a much better store and I doubt I'll have a reason to go to Toyo again.
ETA: Here are two other options for Asian groceries:
Abastos has a small import store. It's on Calle 4 next to the big produce place that's numbered #428 (so the import store would probably be #426 if it were numbered). It's next to all the fondas. It had a wide variety of food from the Middle East, India, east and southeast Asia, Europe, and the US. The prices were similar to what I've seen elsewhere, or maybe slightly cheaper, but they had more things than anyone else I've seen.
There is another branch of this store (Abastos Gourmet) that opened in the spring of 2015 on Pablo Casals just north of Manuel Acuna next to the Waffle House. It's significantly more convenient to get to and there's parking right in front of the store.
Asian Market still has a widest selection I've seen in Guadalajara of Asian groceries with some fresh vegetables, but I go to the one that's most convenient for me since there's generally not one that's significantly better than the others.