Aoyama is a fantastic place for authentic Japanese food and I thoroughly enjoyed my dinner here from start to finish. I do recommend to reserve (and early) as all the tables were reserved when we first stepped in.
We started off with the house special sashimi platter which had a great variety of sashimi. I was told that some of the items were directly from Japan. The items were incredibly fresh and were melt in your mouth. My favourites were the shrimp (huge pieces!), and the sea urchin.
The una-tama (grilled eel egg) on rice was also incredibly savoury and delicious. The egg was just perfectly cooked and fluffy. The eel was great and wasn't fishy at all, but there probably wasn't enough of it.
We ended getting two of the special rolls - the spider roll and the spicy salmon shrimp tempura, and I enjoyed both. You could actually taste the toppings on the inside of the rolls for once because at many places they are over-doused with sauce and mayo, and stuffed with cucumbers and avocado. The spicy salmon wasn't stuffed with breadcrumbs, and there was a ton of soft-shell crab in every piece.
To finish the meal, the green tea cheesecake was perfect. It wasn't overly sweet and had a great balance of cheesy-ness and green tea.
The prices here were extremely reasonable considering the quality of what you're getting and I have no problem paying a premium for authentic and quality food.