A warning to the Kyoto picnicker: You are being watched. One spring morning on the banks of the Katsura River, I sat having breakfast blissfully unaware of this. We had started our day before dawn to beat the tourists to the famous Arashiyama bamboo grove and had worked up an appetite in the process.

Despite the fact that the Japanese have a word for working to death — “karōshi” — many shops and restaurants in Kyoto don’t open until 10 a.m. Fortunately, one of Japan’s most ubiquitous corner stores, Lawson, is open at all hours. It offers far more than the traditional American convenience store, including business services, home goods and prepared foods. Anthony Bourdain loved its egg salad sandwiches, so I selected one from among the array of more-traditional Japanese dishes.

The dawn light was still soft, and aside from the occasional jogger, there was little activity on the riverfront. I slowly unwrapped my sandwich in anticipation. Deep orange yolks in a pale egg purée were spread inside white triangles of Wonder bread. It wouldn’t earn anyone a Michelin star, but I was impressed by its tasty simplicity. As I chewed thoughtfully, I held it up to the light to examine it. A flash of movement in my periphery and a rush of air. Whack! The sandwich exploded from my hand.