An Osaka-based restaurant chain operator and its top manager were fined Wednesday for making foreign student employees work longer hours than legally permitted.

The Osaka Summary Court fined Ichimonkai, the operator of the Kushikatsu Daruma restaurant chain, ¥500,000 and 38-year-old Shohei Yabuguchi, who is the chief manager for all the stores, ¥300,000 as demanded by prosecutors for violating the immigration law.

At the restaurant chain, which serves kushikatsu deep-fried meat and vegetables skewers, 11 foreign students work beyond the 28 hours a week allowed under their visas at several outlets in the city of Osaka between last September and November, according to the ruling.

The defendants admitted to the charges during the court's first hearing last month.

"Defendant Yabuguchi bears a grave responsibility, as he prioritized profits despite being fully aware of the illegality involving foreign part-timers at some outlets at the end of 2015," said Judge Setsu Inokuchi.

The judge added that the company, however, did take steps later to prevent such illegal employment.

Of the roughly 700 part-time workers at its outlets, 200 are foreign nationals, according to the company.

After the ruling, Ichimonkai President Katsuya Ueyama, 56, said, "By learning from this lesson, we will abide by law regarding working hours not only for foreign employees but also for Japanese workers."