Unfortunately, no. There are important reasons why we cannot accommodate dietary restrictions in Japan.
Vegetarian, Vegan, and Gluten-Free Diets in Japan
Vegetarianism, veganism, and gluten-free diets are not as popular in Japan as in the West, so you'll find there's often some confusion as to what you can and can't eat. There are also common cooking ingredients, such as dashi, that contain many components, including fish and gluten products. An ingredient like dashi is the cornerstone of many recipes, and there is no way to not use it.
Omakase Meals
Some meals on the trip are served omakase style, a way that somewhat resembles small plates served to share. You might encounter 15 different plates with just a few bites each in one meal. Moreover, many of the ingredients will be selected only days before the meal, because seasonality is so reverently observed. We won't always know in advance what will be in every meal, which on one hand will immerse you in truly unique, unrepeatable experiences, but on the other hand makes dietary restrictions tricky. This may make substitutions impossibly complex, but it's a beautiful and very Japanese way to eat and contributes a lot to the magic.
Language
Because most of our meals take place off the tourist path, it's nearly impossible to effectively communicate restrictions to chefs and expect alternatives that we can count on to leave travelers feeling well fed.
Food and Culture
It’s important to Wild Terrains to be respectful and responsible in every destination we visit. In Japan, where food is deeply rooted in tradition and tradition shapes the cultural mores, the most respectful choice is to defer to our culinary partners’ knowledge and artistry with ingredients. Their skills have been earned through generations of practice and we want to honor that. The gorgeous meals on the trip would not be the same if we reshaped them to satisfy a Western palette and we want to celebrate their unique identity, just the way they are.