A South Korean employee of home builder Sekisui House Ltd. filed a lawsuit Monday seeking 3 million yen from a customer he said made discriminatory remarks.
So Mun Pyong, 45, is also demanding that the customer publish an apology ad.
The Osaka-based company said it will cover his litigation expenses and allow him to attend the trial during business hours.
Japanese companies rarely extend such support to employees involved in discrimination suits.
According to the complaint, the incident took place in Osaka in February 2005, when So presented the customer with his business card, which was written in Korean and Japanese characters.
The customer allegedly said: "How much money are you sending to North Korea? People like you cause abduction problems."
The customer continued to make discriminatory comments for about two hours, according to the complaint.
So reported the incident to his supervisors, who made phone calls and sent letters to the customer to confirm whether such remarks were made.
The customer denied making the remarks and refused to apologize, according to the complaint.
"It is obvious the customer made the discriminatory remarks, and it is unforgivable even if he is our customer," Sekisui House's public relations department said in a statement.