Do they have Japanese snacks?

Yes with similarities

Yes, but as with most Korean markets, Korean versions of other Asian products are emphasized. This is consistently with the practices of other Asian-owned stores. They carry other Asian products because the clientele demands it. Smaller Asian stores tend to focus on their own specialized cuisine. Larger chain stores like HMart and Lotte (Korean) as well as Great Wall (Chinese) all carry products from all across Asia to the extent that there is the demand.