The Vegetarian Resource Group (English)

Japan Vegetarian Society (English/Japanese)

Tokyo Vegetarian and Health Food Restaurants (English)

ALISHAN (English/Japanese)
ALISHAN, an organic and natural foods catalog company. They have a variety of selections of imported vegetarian items and you can also download their English-version catalog there.

Mansai (Japanese)

Mark's "Being Vegetarian in Japan" (English)