It's sake, which I guess people call rice wine (even though it is produced more like beer than wine). The little purple grape-looking things on the label are
wisteria flowers (for which the real Tsukimizu-no-Ike is known).
And the small building in the photo is more accurate described as a shrine, typically Shinto, although the one in this photo is a combination Shinto and Buddhist shrine. That said, I think the nearby Nikko Temple (Buddhist) handles the majority of the upkeep. I'm not really sure who, if anybody in particular, is enshrined there.