Less than five minutes from the east exit of Shinjuku station. This is not only a good tempura restaurant, but it is also cheap. Their standard tenpura set is 1600 yen and the special one is 1800. You can also get rice refills for free.To get there from Shinjuku station, take Futaba street (the first parallel south of Shinjuku avenue), then make a right in the street where the Mitsukoshi South Bldg is and you'll see the shop on your left.

Francesco's Note:
I had also thought of reviewing Tsunahachi, but Michel moves quicker. I can still beat him, though, for I have additional information.

Tsunahachi is an old chain of very good tenpura restaurants, and as a matter of fact I ate tenpura for the first time in 1982 at the old Shinjuku Honten, still one of the best in terms of atmosphere. When I have guests from abroad and I want them to have a good Japanese meal, I usually bring them here, because success is guaranteed. The menu is very interesting and offers, besides tenpura at reasonable prices, also sashimi and other stuff, so you shouldn't limit yourself to the very convenient sets (I always have the Jotenpura Teishoku). The quality and taste at Tsunahachi are always the same, and you get exactly the same stuff everywhere, and this consistency is the hallmark of a good restaurant chain. Alas, menus are in Japanese only, but you can usually count on wax models being present, so anybody should be able to order. If there aren't any, just remember to order Jotenpura Teishoku, a great combo for 1800 yen (in September 2001).

To go to Tsunahachi in Nakano, just get out of the south exit and go to the last floor of Marui.

In Ogikubo you don't even have to leave the station building. Just go to Lumine's restaurant floor.

In Shinjuku all branches are either near or inside the station, but all sort of difficult to find, but don't give up, because they really are worth a trip.

Here is the complete list in Tokyo and its immediate vicinity. All Tsunahachi branches are in the vicinity of a station. These addresses have been translated by me from Tsunahachi's Japanese web site and some words in the address might be slightly off, but the phone numbers should be OK.

Branch	Phone number	Address
Head Branch	03-3352-1012	Shinjuku-ku, Shinjuku 3-31-8
Tsunohazu-An	03-3358-2788	Shinjuku-ku, Shinjuku 3-28-4
Station Building	03-3352-5652	Shinjuku-ku, Shinjuku 3-38-1 Shinjuku My City, 7th Fl
West Exit	03-5320-8315	Shinjuku-ku, Shinjuku 1-1-2 Shinjuku Metro Building B1
Keio Branch	03-5321-5965	Shinjuku-ku, Shinjuku 1-1-4 Keio Dept. Store 8 Fl.
Hilltopia Branch	03-3342-2788	Shinjuku-ku, Nishi Shinjuku 6-6-2 Hilton Hotel, B1
Opera City Branch	03-5353-0278	Shinjuku-ku, Nishi Shinjuku 3-20-2 Tokyo Opera City
Shinjuku Takashimaya Branch	03-5361-1860	Shibuya-ku, Setagaya 5-24-2 Takashimaya Times Square 13 Fl
Hibiya Branch	03-3581-7330	Chiyoda-ku, Yurakucho 1-2-2 Hibiya Chante B2
Daimaru Branch	03-3211-2783	Chiyoda-ku, Marunouchi 1-9-1 Daimaru Tokyo 8 Fl
Ginza	03-3567-137	Chuo-ku, Ginza 3--6-1 Matsuya Ginza 8 Fl
Aqua City Branch	03-3599-5070	Minato-ku, Odaiba 1-7-1 Aqua City 6 Fl
Asakusa Branch	03-3845-2783	Taito-ku, Hanakawato 1-4-1 Matsuya Asakusa 7 Fl
Kameido Branch	03-5627-8057	Koto-ku, Kameido 5-1-1 Elnade 6 Fl.
Matsudo Branch	047-362-3354	Chiba-ken Matsudo-shi, Matsudo 1-118 Box Hill 7 Fl
Kashiwa Branch	047-148-2179	Chiba-ken, Kashiwa-Shi, Hirosuemachi 1-1 Kashiwa Takashimaya Station Mall 7 Fl.
Ikebukuro Branch	03-5954-8274	Toshima-ku, Nishi Ikebukuro 1-11-1 Metropolitan Plaza 7 Fl.
Nakano Branch	03-3383-9288	Nakano-ku, Nakano 3-34-27 Marui Nakaano Honten 5 Fl
Ogikubo Branch	03-5397-7394	Suginami-ku, Kami Ogi 1-7-1 Lumine 5 Fl.
Tachikawa Branch	042-527-6630	Tachikawa-shi, Akebonocho 2-1-1 Lumine Tachikawa 8 Fl.
Machida Branch	0427-26-3445	Machida-shi, Hara-machida 6-12-20 Odakyu Dept. Store 9 Fl
Mizonokuchi	044-850-0054	Kanagawa-ken , Kawasaki-shi, Takatsu-ku, Mizonokuchi 1-4-1 Marui Family Mizonokuchi 10 Fl.
Yokohama Branch	045-450-2124	Kanagawa-ken, Yokohama-shi, Nishi-ku, Takashima 2-16-1 Lumine Yokohama 7 Fl.