Slice the Persian cucumbers into 1/2-inch thick pieces and sprinkle with kosher salt. Allow to sit for 30 minutes.

Rinse the salted cucumbers in a fine-mesh sieve and pat dry with a kitchen towel.

In a mixing bowl, whisk together rice vinegar, sugar, mirin, sesame oil, minced garlic, and kosher salt to make the dressing.

Combine the rinsed cucumbers with the dressing in a large bowl, cover, and refrigerate for at least 4 hours.

Serve the salad by arranging marinated cucumbers on a plate, drizzling with chili oil, and garnishing with Fresno chili pepper.