Whisk together the rice vinegar, red wine vinegar, soy sauce, sugar, and mustard. Drizzle in the peanut oil and sesame oil while whisking vigorously to emulsify. Set aside.
Bring a pot of lightly-salted water to a boil. Add the asparagus to the water and cook 3 to 5 minutes until just tender, but still mostly firm. Remove and rinse under cold water to stop from cooking any further.
Place the asparagus in a large bowl and drizzle the dressing over the asparagus. Toss until evenly coated. Sprinkle with sesame seeds to serve.
