Bring a large pot of lightly salted water to a boil. Cook udon in boiling water, stirring occasionally, until noodles are tender yet firm to the bite, 3 to 5 minutes. Drain.

Mix honey, soy sauce, sriracha sauce, and rice vinegar in a bowl. Set sauce aside.

Place bacon in a large pan and cook over high heat until fat is rendered but bacon is not yet crispy, 2 to 3 minutes. Add kimchi and garlic; cook for 1 minute. Add the sauce, udon noodles, and sesame oil; stir well. Remove from heat and transfer noodles to a plate. Top with scallions.