Japanese casino mogul Kazuo Okada is out to prove that blood isn’t thicker than water as he attempts to regain control of his sprawling business empire.

Channel News Asia reported that Okada sued his son, daughter, and wife in HongKong after the latter started a boardroom coup that resulted to his ouster from Tokyo-listed gambling firm Universal Entertainment Corp. He also included Universal as a respondent in the case.

The report, however, didn’t mention the grounds of the lawsuit, which Okada filed against his wife Takako, his son Tomohiro, and his daughter Hiromi. But in an earlier interview with Reuters, Okada said the lawsuit against his family is his way to take control of Okada Holdings Ltd., which is the majority owner of Universal.

It would be recalled that Tomohiro and Hiromi, who holds a combined majority shares in Okada Holdings, led the boardroom coup against the septuagenarian billionaire. Records from the Hong Kong Stock Exchange showed that the Japanese patriarch resigned from the company.