In a small bowl, whisk together the soy sauce, brown sugar and ginger. Add the chicken livers and water chestnuts and stir to coat. Marinate in the refrigerator for at least an hour.

Preheat the oven to 425°F.

Remove the chicken livers and water chestnuts from the marinade with a slotted spoon to a plate. Pour the marinade into a small saucepan and bring to a boil over high heat. Reduce the heat to a bare simmer and let cook for a couple of minutes. Set aside.

Line a baking sheet with foil. Place 1 slice of bacon on a cutting board, top with one piece of liver and one piece of water chestnut. Wrap the bacon around both and secure with a toothpick. Transfer the rumaki to your prepared baking sheet and repeat with the remaining bacon, chicken livers and water chestnuts. Baste the rumaki with some of the marinade and bake, basting every 5 or 6 minutes with marinade, about 25 minutes or until the bacon is golden brown. Serve with Chinese hot mustard and plum sauce for dipping.