Wash the English cucumbers thoroughly and slice them into 1/8-inch rounds. Place in a colander, sprinkle with salt, and let drain for 15–20 minutes.

Pat the drained cucumbers dry with a paper towel. In a large mixing bowl, combine cucumber slices with diced crab (or imitation crab) and cubed avocado. Stir gently to mix evenly.

In a separate bowl, whisk together mayonnaise, cream cheese, soy sauce, and sesame seeds until smooth. Adjust for taste.

Pour the dressing over the cucumber mixture and gently toss to coat all ingredients.

Transfer the salad to a serving bowl or plates. Garnish with additional sesame seeds and scallions or radishes if desired. Serve immediately.