As one of the waiters, who has just arrived, points out, "It's like a factory here, but it's working! ". And it's true that this business of permanent Asian fusion (the former Koi has become Yen) is an undeniable success. Crowds attract crowds, and the many counters mean you can sit in front of and around the cooks who deliver sushi, sashimi, teriyaki, gyozas, ramen... There are formulas for two, three or more, and the choice sweeps all over Japan, spilling over a little into the continent. There's enough food to ensure freshness, both raw and cooked, and the young service team keeps up with the hectic pace with a smile.