One unique cuisine that is a must-try for adventurous foodies is offal cuisine. This article which first appeared in Metropolis magazine includes several popular restaurants in Tokyo for naizo ryori.

http://archive.metropolis.co.jp/tokyo/785/localflavors.asp (text follows)

Tokyo’s horumon boom has been going strong for two years now—and shows no signs of letting up. Horumon ryori, a.k.a. naizo, ranges from an animal’s mouth (tongue) to its tail (literally), including all the organs and pipes in-between. Though it may seem intimidating at first, fresh and well-prepared horumon is a dining adventure unlike no other—who knew you could even eat body parts like nodochinko (uvula) or fuwa (lungs)? Textures range from creamy brains to kori kori (chewy) intestines, and the food goes well with most alcoholic beverages, which helps account for its increasing popularity among salarymen and OLs. Here are some of our favorite places around town.

Birdland
While horumon refers to innards taken from cows and pigs, a good place to start may be with chickens. Birdland, one of Tokyo’s most famous yakitori restaurants, has chicken so fresh that it can be eaten rare. Bonbochi is the fatty bits near the tail, grilled up to juicy, savory bombs. Liver is rich and tender, sunagimo (gizzard) is chewy, hatsu (heart) has a nice mouthfeel, while nankotsu (cartilage; below) gives your jaws a workout.

B1, 4-2-15 Ginza, Chuo-ku. Tel: 03-5250-1081. Open Tue-Sat 5-9:30pm, closed Sun-Mon & hols. Nearest stn: Yurakucho.

Yamariki
A shitamachi institution, Yamariki’s original restaurant is undergoing renovation, but the shinkan is still open. This izakaya’s signature nikomi of cow intestines is slow-simmered until tender—the cooks have used the same broth continuously for close to 40 years. Yamariki is known for its yakiton, or grilled bits from pork, including juicy kashira (temples) and chewy teppo (rectum). The restaurant’s knowledgeable sommelier, Mizukami-san, can help suggest French wines to go with your meal.

1-14-6 Morishita, Koto-ku. Tel: 03-5625-6685. Open Mon-Sat 5-10pm, closed Sun & hols. Nearest stn: Morishita (Toei Shinjuku line). www.yamariki.com

Shinjuku Horumon
Shinjuku Horumon and Saisei Sakaba, part of a restaurant chain managed by naizo specialists Ishii Group, are notable for their top-quality products, knowledgeable staff and deep menus. If you’re the type that loves to cook, you’ll enjoy it here—each table has its own shichirin (charcoal stove), which infuses the meats with a better aroma than gas. If you’re the curious type, Shinjuku Horumon offers the most diverse menu, including pai (breast) and sao (tip of the penis). We ordered an assortment platter, and the friendly staff adeptly walked us through all of them; there is also a helpful poster on the wall explaining the menu. The only thing we didn’t like was that the small space quickly fills with smoke.

3-12-3 Shinjuku. Tel: 03-3353-4129. Open daily 5pm-midnight. Nearest stn: Shinjuku, east exit. http://tinyurl.com/shin-hor

Saisei Sakaba
Located on the back streets of Shinjuku-Sanchome, this friendly tachinomiya is our hands-down favorite. The Showa-era décor calls to mind a bygone era, while the six handsome staffers squeezed in behind the counter care for the customers (pictured). We started with brain sashimi—milky and creamy like shirako (cod milt), served with sesame seeds, soy sauce and chopped negi. Then we challenged the grill master to surprise us with five unusual skewers, and he came back with chewy shokudo (esophagus); crispy guts; hizo (spleen), which was similar to liver but with a side of fat; rubbery nodomoto (throat); and meaty komekami (temple). The yudetan (tongue) is simmered all day until tender. The staff was diligent in keeping their work areas and cutting boards spotless—a reassuring sign—and the attentive servers saw that our glasses never went empty.

3-7-3 Shinjuku. Tel: 03-3354-4829. Open daily 3pm-midnight. Nearest stn: Shinjuku, east exit. http://tinyurl.com/saisei

Ebisu Itchome Horumon
This simply designed restaurant features a power vacuum over each table’s gas grill to suck up the smoke. The staff suggested we start off with liver sashimi, which was very fresh but cut too thick. The next course of grilled naizo was our favorite, especially the fatty tontoro (neck) and hearty hatsumoto (aorta). Ebisu Itchome’s signature dish, the kopuchan nabe, is filled with vegetables to balance the fatty small intestines. The loud music explains why our phone calls went unanswered while we were lost for 45 minutes, so make sure you bring along a good map.

1-22-23 Ebisu, Shibuya-ku. Tel: 03-6277-0777. Open daily 11:30am-3pm and 6pm-5am. Nearest stn: Ebisu, east exit. http://r.gnavi.co.jp/g431308 

Guide to popular horumon varieties

tan (tongue) タン
tail (tail) テール
nodochinko (uvula) のどちんこ
fuwa (lungs) フワ
burenzu (brains) ブレンズ
tecchan (large intestines) テッチャン
marucho (small intestines) マルチョウ
sunagimo (gizzard) 砂肝
hatsu (heart) ハツ
nankotsu (cartilage) なんこつ
kashira (temples) かしら
teppo (rectum) てっぽー
tontoro (neck) 豚とろ
hatsumoto (aorta) はつもと
pai (breast) ぱい
sao (tip of the penis) さお
shikin (esophagus) しきん
gatsu (guts) がつ
nodomoto (throat) のどもと
komekami (temple) こめかみ
yude-tan (simmered tongue) ゆでタン