For a 1-day pickles, cut cucumbers into quarters or sandwich slices. Halve garlic lengthwise. Combine everything in a jar with a tight-fitting lid. Refrigerate for 24 hours.
For a crunchier texture, pickle whole cucumbers. Add all the ingredients into a jar with a tight-fitting lid. If the liquid cannot cover the cucumbers, keep adding soy sauce and vinegar at a ratio of 1:3. Refrigerate for at least 3 days, preferably a week. They will keep for 3 to 4 weeks.
To serve the pickles, thinly slice them and drizzle with a bit of sesame oil, if using.