All is quiet at 10:30 a.m. on a Thursday in Shibuya, Tokyo’s famous commercial district. In an alleyway just steps from one of the busiest train stations in the world, a short line of tourists huddles outside of a bar. Finally, half an hour later, the door cracks open and, greeted with a soft “irasshaimase,” or “welcome,” the parties shuffle in to sample one of the rarest dishes in Japan: faux-fish sushi.

“Nowadays, there are many vegan ‘meat’ products,” said Kazue Maeda, one of the four founding employees of the restaurant, Vegan Sushi Tokyo. “But I’m Japanese. What I really used to love is sushi and salmon.”

Her restaurant attempts to fill a relatively unclaimed niche in the local food scene. Even in Tokyo, where much of the country’s vegan population lives, plant-based versions of traditional Japanese food remain challenging to find — most vegan options are Western-inspired dishes like curry rice or vegan hamburg steak.

Vegan Sushi Tokyo is open only for lunch: Although rave reviews keep pouring in from customers, the small business still doesn’t have a storefront of its own and rents out the interior of a bar by day. It serves 10-piece nigiri lunch sets, which include a plant-based Japanese-style “egg,” “shrimp” tempura and beads made out of seaweed that look nearly indistinguishable from salmon roe.

Japan’s culinary culture may be rich and diverse, but it remains reliant on animal products, especially when dashi, a savory broth made of dried tuna flakes and kelp, is present in so many dishes.

Maeda became a vegan six years ago, due to her growing concern over environmental and animal rights issues. It’s a familiar origin story for those who have come to defy the typical Japanese diet by giving up meat, fish and dairy.

“In terms of the vegan movement, I think we’re maybe behind other countries. The number of vegans is very small,” Maeda said. “But there are more and more vegetarian and vegan restaurants in Tokyo, I think because of tourists — especially from countries with many vegetarian people.”