Slice cucumbers into thin rounds or half-moons. If using English cucumbers, no need to peel. For extra crunch, lightly salt the slices and let sit for 10 minutes, then pat dry with paper towels.
In a small bowl, whisk together toasted sesame oil, rice vinegar, soy sauce, maple syrup, minced garlic, and red pepper flakes until well combined.
In a large bowl, combine cucumbers, cilantro, mint, green onions, and most of the sesame seeds. Pour the dressing over and toss gently to coat.
Transfer to a serving dish, sprinkle remaining sesame seeds on top. Serve immediately or refrigerate for 30 minutes to let flavors meld.