Kusumoto is a membership based dinner club that now offers a limited number of dinner seats to the general public. There's a range of courses offered, from which we (expectedly) chose the expensive one, priced around 12,000 at the moment. Almost everything was excellent, including a terrific dish of horse nigiri, a sublime serving of noresore in citrus jelly, a sashimi platter with correctly crunchy madai and okay tuna, four hour cooked abalone, sharkfin rice... the only dud was dessert, which included a ball of freezer-flavored strawberry sorbet. Highly recommended.
Cocoro - I've mentioned it here before, and I'll mention it again as they need and deserve your business. Unreasonably located in Harajuku with pancakes and burgers all around, and operating out of a room that looks like it was supposed to serve an Italian restaurant, they serve modern-Izakaya fare with a handful of western dishes. The ingredients are always excellent, sashimi plates are artfully presented (and a steal), and the chef and hostess are charming (and English enabled). I don't know much about sake but many of the bottles I tried there seemed very good to me. Someone with tabelog cred should vote them up:
Kyoushizuku - what a dud of a Kyoryouri place. I think the chef operates this as a cooking school, or at least that's the only way I can explain the two employees/students snickering in the kitchen. The chef himself didn't seem particularly committed to the fact that the restaurant was open, occasionally coming out to grill this or finish that, but spending the evening talking to a lady friend (not a dinner customer) in a private room. One hour start to finish for a 12 course meal, many items too sweet or otherwise off flavored. Stay away.
Den - I can no longer recommend it at all. I think the turnover in the kitchen brought them to a point where they can no longer control the place. The vegetable dish has reverted to a cheap Italian cafe style salad, over dressed and featuring very sweet/sour components. The chicken was very greasy. Other items had various problems... and the service (I know they think they are being friendly and helpful) is seriously overbearing.
Tirpse - the service is still rough around the edges, and the style is far more Japanese-inflected than at Quintessence, but if you don't go crazy with the wine I think it's not at all a bad place to have dinner at the current price. Everything is perfectly executed, clever, and clean, from the earl grey flavored onion "crisps" at the beginning of the meal, to the gorgeous pigeon, but maybe an unexpected highlight for me was a dish that included mountain vegetables that were magically without any bitterness, but sitting on campari infused couscous. Recommended.