Rodent Found in Miso Soup: Sukiya Closes 2000 Stores

A rat discovered in miso soup at Sukiya’s Tottori Minamiyoshikata branch on January 21, 2025, triggered a food safety crisis that forced nearly 2,000 stores to close and knocked 7.1% off parent company Zensho Holdings’ stock price. The two-month delay before public disclosure compounded the damage, and a second pest incident at a Tokyo location added to investor concerns.

Stores temporarily closed: Nearly 2,000 ·
Stock drop: 7.1% ·
Incident date: January 21, 2025 ·
Location: Tottori Minamiyoshikata branch ·
Pests found: Rat and cockroach

The table below summarizes the key facts documented across multiple news outlets.

Is Sukiya to close most stores in Japan after finding rat and cockroach in food?

The discovery at Sukiya’s Tottori branch on January 21, 2025 sent shockwaves through Japan’s restaurant industry. According to Japan Today, the rodent made its way into the miso soup while employees were preparing ingredients for other dishes. An employee failed to check the dish before serving it to the customer, who noticed the rat immediately and notified staff. The Tottori store was closed for two days following the incident.

Announcement details

Rather than alerting the public immediately, Sukiya kept the incident under wraps for approximately two months. The chain publicly announced the incident on March 22, 2025, prompting an immediate response from investors and consumers alike. The Japan Times reported that Sukiya apologized for failing to disclose the incident sooner, acknowledging the breach of trust with its customer base.

Extent of closures

Sukiya operates around 2,000 branches across Japan, making it one of the country’s largest restaurant chains known for its beef rice bowls. Following the incident announcement, the chain announced it would close nearly all of its stores for thorough cleaning and hygiene inspections. According to reporting from The Straits Times, these closures began on March 29, representing an unprecedented move for the chain. The chain announced it would double down on hygiene measures in response to the incident, implementing stricter checks at all locations.

Reasons for shutdown

The scale of the response reflects both the severity of the contamination and growing public concern. Compounding the situation, a bug contamination incident reportedly occurred at a Sukiya Tokyo restaurant on March 28, 2025, just two months after the rat incident, according to CBS News. This second incident, though not confirmed through official channels, added urgency to the nationwide hygiene review.

Is Miso Soup Vegan?

For those wondering whether this incident carries additional dietary implications, the answer depends on the specific preparation. Traditional miso soup is not always vegan, as it often includes a dashi broth base made from fish, particularly driedbonito flakes. However, vegan miso alternatives are widely available for those following plant-based diets.

Traditional ingredients

Miso paste itself is typically made from fermented soybeans, rice or barley, salt, and koji (a fermentation starter). This base is vegetarian-friendly. However, the liquid that carries the miso — the broth or dashi — is where animal products frequently appear.

Animal product risks

Dashi, the foundational broth in most miso soup recipes, is traditionally made with kombu (kelp) and either bonito flakes or other dried fish. Diners following vegan or vegetarian diets should verify with restaurant staff whether their miso soup uses plant-based dashi. Labels should be checked for dashi ingredients, as some manufacturers produce vegan versions using only kelp.

Vegan alternatives

Restaurants increasingly offer vegan miso soup using plant-based dashi made from kombu alone. Tofu and seaweed remain common vegetarian-friendly additions when the broth is properly prepared. Those with dietary restrictions should always confirm preparation methods with staff, as cross-contamination risks also exist in busy kitchen environments.

What is miso made of?

Understanding what goes into miso helps contextualize why this ingredient appears in so many Japanese dishes. The paste itself has ancient origins, dating back centuries as a staple of Japanese cuisine.

Core components

At its heart, miso is a fermented paste made from soybeans, rice or barley (depending on the variety), salt, and koji mold. The proportions and fermentation duration determine the final product’s flavor profile, ranging from mild white miso to robust red miso.

Fermentation process

The ingredients are mixed, inoculated with koji, and left to ferment for anywhere from a few weeks to several years. Longer fermentation produces deeper, saltier flavors. The process is similar to how certain cheeses develop complexity over time.

Common additives

Beyond the base four ingredients, some miso varieties include additives like bonito flakes, seaweed, or other flavor enhancers. These additions are typically minimal but can affect the product’s suitability for vegetarian or vegan diets.

Does miso soup have animal products?

This question becomes critical for those with dietary restrictions or ethical preferences. The answer is nuanced and depends heavily on preparation methods.

Dashi broth source

Traditional Japanese dashi relies heavily on fish products. Bonito flakes (dried, fermented skipjack tuna) provide the umami backbone for most restaurant-style miso soup. Without specifying otherwise, customers should assume their soup contains fish-derived ingredients.

Miso paste variants

While the miso paste itself is usually vegetarian, the ready-made soup mixes sold in stores sometimes include added seasonings that contain animal products. Reading ingredient labels carefully before purchase is advisable.

Vegan verification

To confirm a miso soup is vegan, diners must verify both the miso paste ingredients and the broth preparation. Asking specifically whether “katsuobushi” (bonito) or other fish products were used is the most direct approach.

Does Tokyo, Japan have a rat problem?

Urban pest issues are not unique to any single city, and Tokyo’s dense population and extensive food service industry create conditions where rodent sightings can occur. Understanding the broader context helps frame the Sukiya incident within larger food safety challenges.

Urban pest trends

Major metropolitan areas worldwide face ongoing pest management challenges, and Tokyo is no exception. The city’s extensive underground shopping districts, food streets, and dense restaurant concentration create favorable environments for urban pests.

Link to food incidents

Individual incidents like the Sukiya discovery can reflect broader systemic hygiene challenges rather than isolated failures. Restaurants serving high volumes of customers face inherent pest pressures that require constant vigilance.

Control efforts

Japanese food safety regulations mandate specific pest control protocols for commercial food establishments. Regular inspections and mandatory pest management contracts are standard requirements for operating restaurants in Japan.

The pattern that stands out is the delay between discovery and disclosure. That two-month gap meant investors and the public learned about the contamination alongside news of a second pest incident, creating a compounding effect that intensified market reaction beyond what the initial discovery alone might have triggered.

What customers and investors should watch

The immediate aftermath has settled, but questions remain about longer-term changes. Customers should monitor whether Sukiya implements visible hygiene improvements during store reopenings. Investors will want to track whether the company’s hygiene investments translate into restored stock value or whether additional incidents emerge.

The chain’s next moves — particularly how transparently it communicates future incidents and what concrete operational changes it implements — will likely determine whether this crisis becomes a turning point or a prolonged reputation damage case. Watch for Sukiya’s next quarterly earnings report: if hygiene investment costs spike alongside reopening, investors will get a clearer picture of just how deeply this incident affects the company’s financials beyond the initial stock drop.

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