Cut the mochi in half horizontally, then cut into 1.5 cm squares. (You don't need to be super precise.)
Transfer the mochi onto a sieve, and let them dry (under cold air if possible) for 5~7 days.
Heat up deep-bottomed frying pan or fryer with vegetable oil and deep-fry the dried mochi. They'll burn if the oil temperature is too high, so deep-fry on a low temperature for a while.
Once they turn golden brown, drain away the excess oil on a paper towel. Transfer into a plastic bag with the salt and sugar, then shake them to seasone and they're done.
Story Behind this Recipe
I created this recipe to enjoy leftover mochi. I added a small amount of sugar, and made it sweet and salty.
When mochi contains a lot of water, oil will splatter while deep-frying, so dry it for 5~7 days if you can. I used smooth table salt instead of coarse salt, but you should adjust the seasoning to your liking.