Cook the macaroni according to the package instructions until tender.

Drain and rinse with cold water, then let the macaroni cool completely.

Add the shredded carrot, green onions, and finely shredded onion to the cooled macaroni.

Drizzle with rice vinegar and mix well.

In a separate bowl, combine the milk, salt, sugar, Kewpie mayonnaise, and black pepper. Mix until smooth.

Pour the dressing over the macaroni and vegetables. Mix until everything is evenly coated.

Cover and refrigerate until chilled.