KAWAGOE, Japan — Several years ago, an investment subsidiary of the agricultural giant Cargill bought a group of so-called love hotels, which typically rent rooms by the hour, including the neon-lit Hotel Shine in this sprawling Tokyo suburb.


Though many industry analysts say love hotels in Japan are a good cash flow business — catering to young married couples living with family, as well as to philanderers, prostitutes and even penny-pinching tourists — the Cargill subsidiary was disappointed with its results. The unit, CarVal Investors, sold the 10 properties last week for about $20 million, far less than the $60 million it paid for them in 2004 and 2005.


It might have been just another fire sale. After all, many American funds invested in distressed properties at the height of Japan’s economic woes without success.


But CarVal is now under fire from former employees and business partners in part because of the tough tactics of the new owner: an affiliate of a Japanese developer, the Kato Pleasure Group. Immediately after closing the sale on Thursday, the buyer dispatched groups of black-suited men to force out hotel workers and even hotel guests, barricading the entrances with wooden fences.


About 300 hotel workers have been left in the lurch. They are planning a rally outside Cargill’s Tokyo offices this week to protest their treatment. Two executives who managed the hotels under contract during CarVal’s ownership have refused to leave and remain inside Hotel Shine — a standoff that has drawn the attention of the local police.


The most vocal opponent of the sale, however, is CarVal’s former partner, Alchemy, which had a contract to manage the hotels. In registered letters, filed in court, Alchemy contends that CarVal violated business agreements by selling the properties before their contract was up in October 2014.


In submissions to both the local Tokyo and Saitama Metropolitan Police, Alchemy also contends that Kato Pleasure has ties to Japan’s criminal underground and that CarVal ignored repeated warnings — backed up by outside research — not to go through with the sale.


“Our complaint to CarVal is that they ignored credible advice that they were dealing with a suspected organized crime entity,” said Miro Mijatovic, Alchemy’s chief executive.


CarVal says Alchemy’s accusations are baseless. Kato Pleasure also denies that it has criminal links, but it provided little response to questions posed to a spokesman at its Tokyo headquarters and to company representatives at Hotel Shine. The new owner of the hotels is Plus Ten Mind, a company affiliated with Kato Pleasure that shares the same chief executive.


Ann Folkman, a managing director at CarVal, said there were sound reasons to do business in the hotels. “While leisure hotels may sound salacious, they are a legitimate and longstanding industry that caters to the privacy needs of young Japanese adults, who frequently live with their parents or in company-provided housing,” Ms. Folkman wrote in an e-mail. “As with many of the hotels we have invested in across the world, the investment strategy was to run a compliant business, create sufficient scale and operational regularity and then exit to a buyer who could see the value of the business.”


CarVal’s exit came shortly after 3 p.m. on Thursday, when groups of men who said they were affiliated with Kato Pleasure made a coordinated sweep of the hotels, forcing out the staff, emptying hotel rooms of frightened guests, putting up makeshift fences and changing the locks in preparation to install Kato’s own management and workers.


Takashi Hayashi, the chief executive of Urban Resorts, a unit of Alchemy contracted to run the hotels’ daily operations, who has refused to leave Hotel Shine, seemed shaken as he spoke to a reporter through a tall fence on Saturday. He was flanked by two men who he said worked for Kato Pleasure, who refused to speak to a reporter. Around the compound, six workers were putting the finishing touches on barricades at the hotel’s entrances.


“I’m fine,” Mr. Hayashi said. “I have no intention of leaving.”