Training Relationship

Xiao Bai is a teacher with two little siblings. Their father left them with a huge debt (20 million) from the Zhuo Shan Group, which is a mafia group. The third generation leader, Zhuo You, came after them after their father fled from the country. Once caught by Zhuo You, he was asked to pay back the debt with his 'body'! Just what does he mean by that?