Umeshu is another way of imbibing umeboshi. It's Japan's sweet plum liqueur, which comes in two different forms. Then there's fuku-cha, a green tea-based, umeboshi-studded hot drink drunk at ...
It uses umeboshi (salted Japanese plums), but what you put inside can be just about anything — fish, meat, veggies, even cheese — as long as it fits and tastes good. Feel free to experiment.