An acclaimed Japanese prix-fixe restaurant that most of us were not lucky enough to dine at, Noodle In a Haystack, has closed, and its owners are going the fast-casual route in the hopes of finally turning a decent profit.

It's a familiar refrain in the San Francisco restaurant scene, where the rising costs of everything, from ingredients to rent to labor to healthcare, have made many small businesses unsustainable. The couple behind the highly acclaimed, 12-seat, Richmond District restaurant Noodle in a Haystack have shut their doors after four years because their tiny operation no longer made financial sense.

Clint and Yoko Tan tell the Chronicle this week that they shuttered the always sold-out restaurant last month because "It felt like we’ve been running in place the last few years," and the physical toll of running the tiny restaurant, just the two of them, had become too much, and was generating too little profit. This is despite charging $306 for their nine-course ramen tasting experience, with beverage pairing, having a waitlist for seats that was 10,000 people long, and not having any other full-time employees besides themselves.

And the closure comes despite an early rave review by the Chronicle's Soleil Ho, and being named one of the best new restaurants in the country in 2023 by the New York Times, and Bon Appetit.

Restaurant profit margins are notoriously thin, and in an expensive city like San Francisco, they can get even thinner — unless you can accomplish things at scale, and with multiple turns per night. The Tans had just two seatings per night, and sometimes were only open two nights per week, sometimes three. Nonetheless, Yoko Tan reportedly landed in the hospital twice because of the physical toll — Chronicle critic MacKenzie Chung Fegan noted last fall that when she finally snagged a reservation after two years of trying, the restaurant had to reschedule at the last minute because Yoko Tan had come down with COVID.

Now, though, more San Franciscans will be able to try the Tans' food, at least one type of ramen dish anyway. They are set to open a fast-casual restaurant this winter at Thrive City, by the Chase Center, called Mazé, specializing in the "dry" ramen style known as mazemen.

As the Chronicle notes, Mazé is moving into the 30-seat space that had been occupied by the wine bar GluGlu. And the Tans plan to serve a couple versions of mazemen that appeared on the Noodle in a Haystack menu, including creamy tan tan, and a spicy version made with yuzu kosho, chicharrón, lime, smoked fish powder, and charred pork belly. There will also be fried chicken, inspired by Japanese convenience store chain Lawson, and the naturally leavened nama doughnuts that Yoko occasionally made for the restaurant as well.

More California-influenced, seasonal versions of mazeman may come as well, with one they mention to the Chronicle involving tomato dashi and burrata.

According to the description on the Chase Center site, "Mazé is derived from the Japanese word meaning 'to mix' or 'to blend,' paired with Men, meaning 'noodle.' Together, the name refers to a style of ramen focused on mixing noodles with sauces, oils, toppings, and textures before enjoyment. Rooted in recipes developed over the last decade, the concept emphasizes bold flavors and carefully sourced ingredients."

Reportedly, the Tans are also on the hunt for a second space in the city for a mid-range restaurant of some kind, though they are not announcing any details on that.