my favorite yakitori shops are the ones that server pork instead of chicken. there's one in Asakusa-bashi called "Nishi Guchi Yaki Ton" (west exit grilled pork) that was located under the JR tracks by the west exit of Asakusa-bashi station. A greasy, filthy, smoke-filled stand up restaurant that had room for about 10 customers inside the place, but another 30 or more spilling out down the street using makeshift tables. Like the restaurant name (Yaki Ton sounds a lot like Yaki Tori, but means grilled pork instead of grilled chicken), the menu is a tongue in cheek play on a yaki tori shop menu - there is even pork tsukune. The guts sashimi is great too. (Unfortunately, Nishi Guchi Yaki Ton moved to become a real sit-down, inside restaurant. Same food and customers, but the ambience was better at the old place.)