is fresh tuna (for sushi) ok in the fridge overnight?
First off, while I certainly don't want to be the wet blanket at the party, are you aware that there was a nationwide recall last week of a lot of sushi-grade Yellowfin tuna due to Salmonella poisoning? I don't have the specifics at my fingertips, but it was all over the news, & some folks have been hospitalized. Just wanted to give you a heads up that you may want to check out the news reports (websearch yellowfin tuna poisoning or recall) to be sure that's not what you purchased. Again - don't want to be a wet blanket, but don't want to see people sick either. Don't know where H-Mart sources their sushi-grade tuna from.
That said, your tuna should be fine overnight snuggly wrapped in plastic wrap & nestled in a bed of ice, just like they do at your local fine Japanese restaurant. Just make sure you check the ice frequently so your fish doesn't end up sitting in a pool of water.