Very spicy, down-home Thai cuisine is what draws the customers to this extremely casual hole-in-the-wall spot, located inside an ancient basement arcade next to Asakusa subway station. The wide-ranging menu includes standards like curries, noodles and spicy salads, plus many dishes from the Isan region of northern Thailand. We'd recommend a thorough perursal of the menu (in Japanese and Thai), paying special attention to the page of chef's recommendations.
With its rickety tables and utilitarian stools, it seems like the kind of place that would welcome walk-in customers, but in fact reservations are essential. (We were lucky enough to get a spot just after opening time if we promised to leave before 7pm.)
Most dishes are priced in the Y700-800 range, similar to those popular Thai chain shops in town, but the food is definitely a cut above. If you're not in the mood for beer, Spanish wine runs Y1800 a bottle; budget around Y2500 for dinner and drinks.
This book will introduce you to more than twenty of Japan's favorite specialty foods that are less well known abroad, along with a guide to the best places in Tokyo to try them and expert tips on what to order. From Bento.com.