Combine vinegar, ginger, and maple syrup and bring to a boil. Cook uncovered over medium heat 10-15 minutes and set aside. Cut off 1/2" of each lower stalk of asparagus. Bring water to a boil, cook asparagus until tender. Remove from heat and rinse with cold water. Combine garlic, oil, salt and soy sauce with vinegar mixture. Arrange asparagus on a plate. Cover with marinade and refrigerate 1-2 hours before serving.