This is mum's favorite fruit & is in season now or ending soon, she had finished boxes of it by now. (Saw Lychee also same time in season now with similar packaging too so be careful not to mistaken the two ...)
I only know it as "Yang Mei" in Chinese and only from the label do I know its English name as "Arbutus". What we had here were from China but a search in the internet showed few replies.
It is supposed to taste refreshingly sour plus some sweetness & well known to have a good cooling effect for a bad sore throat.
A simple way taught by lovers is to wash them & then sprinkle some salt over them (was just recommended on adding both salt & sugar together tasted good too by the vendor but hadn't tried adding both yet). This way will enhance their flavor and tasted fantastic especially taken out cool from the fridge.