"Not guilty."

Chen Yiyi briefly answered each charge read by the judge. She had little else to say during her June 2023 arraignment at a federal courthouse in New York.

Chen is a former employee of Wuhan-based Hubei Amarvel Biotech, a Chinese chemical manufacturer.

She acted as an interpreter for Wang Qingzhou, an executive at the company, and helped with website design. Weeks earlier, both Chen and Wang were detained by the American authorities in Fiji on suspicion of smuggling fentanyl precursors into the U.S.

A Nikkei investigation has found evidence that this smuggling operation had a presence in Japan.

'An ordinary young woman'

The two were poised to ship tons of precursor chemicals to New York. U.S. authorities uncovered their plans, which included trying to manipulate Mexican drug cartels, through a sting operation.

Prosecutors' indictment portrayed Chen as a coldhearted, vicious member of an international drug-smuggling ring. But she often appeared frightened during the trial, seemingly unable to grasp her sudden reversal of fortune.

"She looked like an ordinary young woman you would find in any neighborhood," said a journalist observing the trial.

'100% stealth shipping'

Amarvel Biotech played a key role in a pipeline for fentanyl chemicals going to the U.S., according to American authorities.

A picture of the sophistication of its methods can be gleaned from the history of its activities online.

Amarvel sold chemicals on several specialty e-commerce sites. Website and social media histories show evidence that at least 10 individuals were involved in sales. They worked in English, Spanish and other languages to promote their fentanyl precursors.

The company used various tricks to ship these items, including labeling them as dog food, nuts, beeswax, engine oil and other everyday goods to hide the contents from customs inspectors. After shipping them out of China, Amarvel would reroute them through additional locations to disguise the point of origin.

"Regarding the customs risk in the U.S., about 99% can be cleared," Wang and Chen told an undercover Drug Enforcement Administration agent, according to court documents.

"Perhaps 1 out of 1,000 orders might be detained," but "we may still bring the goods out through some other methods," they said.

They also revealed that they had hidden depots in Mexico, the U.S. and elsewhere.

A web of companies

To conceal its operations, Amarvel operated a widespread network of affiliated companies in China, Japan and the U.S. An open-source intelligence (OSINT) investigation by Nikkei brought new facts to light, suggesting a cross-border smuggling organization that covered its tracks.

Nikkei used company databases and corporate registries in each country to research personnel and financial ties. The organization's deep ties to Japan stood out. Firsky, a company registered in the city of Nagoya, appears to have served as a command post for its operations.

The first clue was found in U.S. court documents, including unreleased materials.

"At one point during the March 2023 meeting in Bangkok, Chen explained that Amarvel Biotech had two bosses, Wang and 'another one' in Japan," according to a court document. When the undercover agent asked to meet the other boss, Wang placed a video call to a "Mr. Xia," the document said.

At her trial, Chen testified that Mr. Xia was "the boss in Japan" and that she had worked at various times for four different companies, including Amarvel Biotech and Wuhan Pharmaceutical, in which Fengzhi Xia had invested.

Combing through Facebook, WeChat and other social media led Nikkei to a Chinese man named Fengzhi Xia.

Xia lived in the city of Naha in Okinawa. He espoused the Confucian ideal of shendu, which calls on people to always exercise self-control, even when alone. In his profile picture, he appeared to be an East Asian man with a buzz cut.

He had only six Facebook friends and just one follower, a person related to Vietnamese pharmaceuticals. Xia would post pictures of high-rise buildings in Wuhan.

Hiding a multitiered structure

Among the people with the same Chinese character as their surname, there are not many with character combinations in their given name that would read as "Fengzhi."

Searching through Chinese corporate databases Qichacha and TianYanCha revealed something else unexpected: Xia was a shareholder in at least 16 companies in Chongqing, Beijing, Tianjin and Wuhan. They were headquartered in different locations and ostensibly operated in a wide range of fields, including construction, design and information technology.

Among these, Xia held a 100% stake in a Wuhan company called Firsky International Trade, where he was listed as the legal representative. In July 2024, this company's auditor, a Wang Qingzhou, suddenly resigned. This auditor had the same name as Amarvel's Wang Qingzhou, who was then on trial in New York.

At the same time that Wang left Firsky, the description of the company's business changed significantly. Until then, its license had listed freight import and export, import-export agent, and chemical product sales as part of its business. But any indication that the company was involved in exporting drug precursors was removed.

Tracing the contact information of the Xia at Firsky led to seven other Chinese companies. At one of them, the top shareholder was the same person listed as president of Amarvel. Xia and this president were connected through the operations of multiple companies.

The Japan connection

Firsky International Trade operated under the Firsky brand. On its English website, the company said it was 100%-owned by "Japan Firsky," located in Japan.

The website said all of its products shipped from Japan by FedEx, UPS, Japan Post and other services, arriving in five to seven business days.

The image of the factory used on the website was the same as the one on Amarvel's now-defunct site. The site also showed what appeared to be company headquarters in Japan. On pages for specific chemical products, there were many records of Firsky selling Amarvel-manufactured products. Firsky sales representatives used the same social media usernames as those at Amarvel.

"A comprehensive analysis of open-source information and digital trails reveals that Amarvel and Firsky operated via an intricate web of interlinked companies, websites, and sales representatives," said George Katz, an investigator on the financial investigations team at Bellingcat, one of the world's leading OSINT organizations.

Firsky is registered in Nagoya's Nishi Ward. The surname of its registered representative is written with the same Chinese character as Xia, adding to the evidence that the Amarvel "boss" used Japan as a base of operations.

While operating the smuggling organization, Xia meticulously covered his tracks, working as a behind-the-scenes fixer. But there was one instance where he came into open view.

In March 2023, a chemical trading company in Japan was having difficulty procuring certain gas products. Hoping to buy them from China, the company was introduced to a person named Xia calling himself president of Firsky. Both sides communicated several times, but it became clear that Firsky did not handle the gas products in question. Contact stopped after that.

This story was told by a representative at the chemical trading company when asked by Nikkei to explain a statement on Firsky's English claiming the two sides had "a long-term cooperative relationship."

The representative said the Japanese company had "no history of transactions, capital relationship or personal interactions" with Firsky. Xia may have tried to spin a few contacts with established players in the chemical industry into a track record to bolster Firsky's credibility.

An 'easier' place to operate

Firsky may also have sought reputational and other benefits from having a Japanese presence.

There are almost no confirmed cases of crimes related to fentanyl involving Japan. Unlike China, where the precursors are produced, or Mexico, where drug cartels operate, it is not high on international authorities' watch list. Some note that packages coming from Japan tend to easily clear customs.

"It is not known or so common for many drug traffickers to go to Japan, so that makes it more easier for a drug trafficker from Mexico, or even from the United States, to travel to [Japan] and look for the precursors," said Margarito Flores, a former member of Mexico's Sinaloa cartel who now works with the DEA.

Back in the New York courtroom in January 2025, Chen sought to defend herself, explaining how she had come to spend half of her life at Amarvel. She had earned degrees in media production and international communications, and for a time she had lived in Italy working for a luxury brand. Her future looked bright.

Then came the COVID-19 pandemic.

Chen returned to her native Wuhan, but the city's lockdown dragged on. Hoping to use her language abilities, she took a job at Amarvel to pay her living expenses.

Chen served as an interpreter in all business discussions related to fentanyl, her former Amarvel supervisor, Wang, testified during the trial.

Nikkei sought comment from both Chen and Wang after their convictions.

Chen's lawyer, Marlon Kirton, said, "We cannot discuss this until sentencing." Wang's lawyer, Leo Aldridge, also declined to comment.

Sentencing for the two is set for August.

Everything in the case comes back to Xia, still in the shadows. Nikkei went to Nagoya in search of answers.