1. Cut octopus legs diagonally in 5mm.

2. Place the octopus on an ovenproof plate and pour on shiodare. Microwave on 600W for 30 seconds. (15seconds on 1200W)

3. Put some roasted sesame seeds in a dish and serve with the octopus. Dip the octopus into the sesame seeds when you eat.

For how long you should cook with your microwave oven, see Cooking Time vs Wattage Conversion.
For more tips of using Microwave Oven, see Sachiko's Guideline to Microwave Cooking.