The worst fights we've ever seen at Sushi Den haven't been over the last piece of o-toro, but over the last seat at the sushi bar on a Friday night. And that's odd, because we'd punch a nun if she was standing between us and some of the brilliant, beautiful, achingly fresh fish brought in by the convoluted and murderously expensive delivery system that Toshi, Sushi Den's owner, has been laboring for twenty years to perfect. As a result of those Herculean efforts, you can be eating fish on South Pearl Street on Saturday night that was sold Saturday morning on the floor of the Nagahama market in Kukuoka, Japan, and was swimming in the ocean on Friday. There aren't many other restaurants where you can do that -- none in Denver, and few in the country. As a result, this is the only place in town where we'll lay out the greenbacks for real o-toro, where we'll wait an hour or more for surf clam and eel, where we'll fight off that nun for the bright-orange uni presented in a simple slip of black seaweed.