Always being able to get a room is one of the benefits of having your own inn.
I went down a bit of a rabbit hole on the bottle— that's actually probably mikanshu, a kind of mikan liqueur. There is actually a wide variety of citrus-based wines, brandies, and liqueurs, and I even found a mikan sake.
Mikanshu is apparently quite sweet, and tastes, unsurprisingly, like mikan juice, but an example I found was 12.5% alcohol by volume (a little less than wine or sake, but nearly double that of beer) so I expect that you (or You) could easily get smashed on it.