The former operators of three sushi outlets have been fined more than $380,000 for ripping off workers including junior employees and vulnerable visa holders.

Key points: Tokyo Sushi bars in regional New South Wales were targeted by the Fair Work Ombudsman

Tokyo Sushi bars in regional New South Wales were targeted by the Fair Work Ombudsman Employees were underpaid for minimum weekday rates, casual rates and penalty rates

Employees were underpaid for minimum weekday rates, casual rates and penalty rates Judge Philip Dowdy said there was "no excuse" for underpaying and exploiting workers

Toyko Sushi bars in regional NSW at Gosford and Newcastle were targeted and taken to court by the Fair Work Ombudsman after inspectors found evidence that 31 employees had been underpaid in 2016.

Owner Kiyoshi Hasegawa was personally fined $63,936 for her role in the underpayments at two Tokyo Sushi outlets at the Erina Fair mall in Gosford and another at suburban Fletcher in Newcastle.

Two outlets owned by Ms Hasegawa and her family companies, Hasegawa & Ye International and Heiwa International, were fined $150,120 and $169,000 respectively.

Fair Work Ombudsman Sandra Parker said visa holders were particularly vulnerable to exploitation and warned the regulator is cracking down on underpayments in the fast food industry as a priority.

"Young migrant workers can be particularly vulnerable to exploitation if they are reluctant to complain due to visa concerns or unaware of their workplace rights," Ms Parker told the ABC.

"We take the blatant underpayment of vulnerable workers particularly seriously, and this has been supported by the Court's substantial penalty.

"Inspectors will continue to conduct targeted audits across the fast food, restaurant and cafe sector and we will hold employers accountable if they are not meeting their lawful obligations."

'Employees are entitled to respect'

The total underpayments by Tokyo Sushi exceeded $70,000 with underpayments of minimum weekday rates, casual rates and penalty rates for weekends and public holidays.

Hasegawa & Ye International and Heiwa International were also fined for breaking laws on superannuation entitlements, record keeping and obligations on minimum engagement periods.

In his ruling, Judge Philip Dowdy said there was "no excuse" for the owners' decision to underpay and exploit their workers.

"Persons who engage in business activities … are under a strict obligation to pay their staff the just entitlements of the staff in accordance with law, whether the relevant employer is a major corporation or, as here, a family business," Judge Dowdy said.

"Employees are entitled to respect and part of that respect is to pay them their full entitlements which must be recognised and known to the employer."

Judge Dowdy ordered that Ms Hasegawa and the two companies backpay employees within 28 days.

Hasegawa & Ye International and Heiwa International have been ordered to commission an external audit to rectify any additional underpayments and to display workplace notices on worker rights.

Fair Work Ombudsman inspectors discovered a range of underpayments when they targeted 40 sushi outlets in New South Wales and south-east Queensland.

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Ms Hasegawa, Hasagawa & Ye International have not operated the Tokyo Sushi outlets at Gosford since July 2017.

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