SEOUL — On a frigid winter evening in Seoul, a college student raced out of a popular bistro and vomited near my feet. The owner, Im Choo-sung, followed him out the door. “Would the kids please throw up in the bathroom?” he announced. “The neighbors get angry at all this.” Then 49-year-old eccentric greeted me. “Hey, American,” he said, pointing to a nearby sign. “We had 13 people pass out from our spicy noodle soup last year. They all went to the emergency room.”