I'd love to share Japanese Shojin ( vegetarian) restaurant in Roppoingi.
Restaurant shojin offers the menu of Shojin cuisine. Shojin means food that Buddhist priests cook for dairy meals. The cooking doesn't require any animal proteins.
However, the regular meal is used traditional dashi stock, which contains bonito flakes infused soup. If you make a reservation in advance for vegan menus, the chef will make dashi with vegetable stock.
This place I'm sure the vegetarians and vegans enjoy authentic Japanese food.
Shijin Sougo reantaurant