Combine the tamari, vinegar, and sesame oil. Mix well. Pour into dipping dishes and top with the green onion, red pepper flakes, and sesame seeds.
Cut the cucumbers in thirds widthwise and scoop out the seeds with a butter knife or small spoon, creating hollow tubes.
Cut the cream cheese into strips as long as the cucumber lengths and stuff into the cucumber pieces. Continue to fill the cucumbers with the crab, avocado, and carrot. Slice into rounds and serve with the dipping sauce.