Four people are under arrest for threatening and forcing a female employee to perform the "dogeza" extreme form of apology at a convenience store in eastern Hokkaido, police said.

Hiroki Matsunaga, 38, Tomokazu Kabeya, 38, and two others were taken into custody. One of the four is a woman, the police said. They are all from Kushiro in eastern Hokkaido.

According to the Kushiro Police Station, the four appeared at the convenience store in Kushiro at around 5 a.m. Sunday and each ordered coffee. But when the teen female employee served "hot" coffee, the four burst into rage, saying they ordered ice coffee.

Then they forced the girl to sit on the floor in the traditional "seiza" form, one of the formal ways of sitting, for about 20 minutes and eventually perform "dogeza" — the extreme form of apology by bowing deeply until the forehead touches the floor — the police said.

The four also threatened to "bring dozens of our foot soldiers" to the store, according to the police.

Among the four, Kabeya has denied abusing the employee and claimed he was drunk at the time. The other three have owned up to the intimidation, the police said.