Once you get past the crowded, cramped waiting area and taste any of the rolls on Tenjins menu, you will see that it is crowded for a reason. The sushi is always fresh, as tasty as it comes, usually comes quickly and is creatively served. Sitting at the Sushi bar is always enjoyable due to the kind and humorous chefs. The name of the game is 'complicated' at Tenjin- try new things. Try the "special" rolls where they don't tell you whats in it. You'll be happy you did.
All in all- Its not the most beautiful restaurant, or the most high class- but there are 10 year olds eating eel there for a reason. Its really, really good.