Soak the chickpeas overnight in enough water to cover them by 2 inches. Add kombucha or pickle brine to soaking water.
The next day, drain, rinse and cook beans until "al dente" on stove, simmering 45 to 60 minutes, or slow cook on low for 4 to 6 hours.
Drain cooked beans, and let cool.
Add beans, 1 1/2 teaspoons (8 ml) salt and mince garlic and add to the bowl of a food processor. Squeeze lemon juice in and add umeshu. Process on low to incorporate ingredients for 10 to 15 seconds.
Remove pits from umeboshi and dice finely, along with shiso leaves.
Add tahini, umeboshi, and shiso. Process until it starts to become smooth.
Drizzle olive oil into food processor while spinning.
Transfer to a bowl and serve. Due to the high protein content, hummus is relatively perishable. Will keep for refrigerator for 3 days. Freeze for longer storage.