While not a pickle in the traditional sense, these mushrooms fill that niche of flavorful veggies that compliment a larger dish. These mushrooms have a shorter shelf life that the other quick pickle recipes, but this is rarely a problem. I make these for topping bibimbap, and they don't last more than a day or two.
Try white/button or shiitake mushrooms. Change the ratio of sake/mirin, or add rice vinegar for more tang.