"Made from Steeping ripe green Ume fruit in Shochu" - ume are plums from the prunus mume tree, and shochu ('burnt liquor') is an old-fashioned japanese drink made from fermented barley or rice with a distinctive sweet/sour taste. Alcohol content is 10%. Apparently this drink is very popular in Japan.
I bought it because friends coming back from HK had bought me a bottle of Choya extra aged, which I loved. When it was finished i checked UK availability, but it is *very* expensive, so I thought I would try this version: same brand, but without the aging (or the plums in the bottle). I think this is very nice too, but not as wonderful (and i use the term on purpose!) as the aged Choya. More affordable, though, and very drinkabel. I enjoy it after a nice meal as an 'digestif' for which it is purrfect!