I was very conscious of my position as an interloper and tried to stay out of the way, interfering as little as possible with normal activity. Besides, it was really interesting to stand back, protected by a stack of boxes, and take in the atmosphere of the place as I plotted my next foray.

Despite my concern about getting in the way, everyone greeted me warmly. As far as I could tell, I was the only gaijin in the building, and one of the very few people not looking to buy, but this seemed to bother no-one. Some people who knew a little English described to me what they were selling or asked where I was from. Most stallholders gladly showed off their wares, offering a small sample with the word "dozo", "eat" or "taste". I replied, "arigato", and accepted what was offered. It was always delicious, although I was often not entirely sure what I was eating.

The people selling the larger fish possessed impressive collections of knives, and were obviously showing off their skill with their blades when they saw me standing next to them, camera at the ready. Some of the knives had metre long blades and I watched as one man neatly divided a large fish in half - head to tail - with one smooth stroke.

Tuna stalls were everywhere. Each one had stacks of headless, frozen tuna carcasses piled at the back and, when someone requested a piece of the fish, the vendor simply pulled a carcass off the pile, placed it on a band saw and, eyeballing where to make the cut, sliced off the requested steak.

I wandered around the place for almost two hours, until the crowd began to thin. By 8 a.m. the place seemed ready to close for the day so I left the hall and worked my way through the parking lot as the last of the trucks were being loaded.

I headed slowly back towards the subway station. Some of the shops that had been closed on my way here were now open for business, and in fact were small restaurants. The weather was warm, so the fronts of most of them were open to the pathway, with a short curtain hanging across the top of the entry. Each restaurant was very small, with no more than a counter and a row of stools. The customers were the people who worked in the area - men and women seated at the counter, dressed in their work clothes and those calf-high boots that I had seen at the fish market. It was breakfast time and people were slurping bowls of noodles or eating sushi and sashimi. I suddenly remembered what had got me out of bed in the first place. I was really hungry.

Clearly this would be a far more interesting breakfast experience than any hotel restaurant. I poked my head into several establishments, looking for one that appealed to me and had a free seat. After about 10 minutes, I found a place selling sushi and sashimi that had an open seat near the door. Sashimi for breakfast was going to be a first for me. The proprietress greeted me curtly with the standard "irashaimase" ("Welcome"), and the other diners briefly glanced up at me before returning to their eating and conversations. With my limited Japanese, I ordered a selection of fish, which was quickly prepared and served with a cup of green tea.

Three and a half hours after getting up and needing a cup of coffee I was slowly eating my breakfast, being ignored by customers and the proprietress. The ambience may have lacked something, but the fish was very fresh and absolutely delicious. My friend had been absolutely right - sashimi is best eaten before noon.