Remove the shells and veins from the shrimp.
Rinse the shrimp thoroughly and pat dry.
Mix gochujang (Korean red chili paste), soy sauce, sugar, minced garlic, chili powder, and sesame oil to make the marinade sauce.
Slice onion, hot green chili peppers, and green onion thinly.
Place shrimp, vegetables, and marinade sauce in a bowl, and mix well until evenly coated.
Transfer to an airtight container and let it marinate in the refrigerator for 2-3 hours.