DNA testing is used to select several humans or creatures who may be "descendants of the Yama Calamity". In order to determine who the "sons of Yama" were, the "Harmony Family Plan" was drawn up – to unite all the people who might be the "sons of Yama" into a family and live together. The captain of the Countermeasures Section 1 of the Countermeasures Bureau, Ranzaki Huanghuo, was forced to participate as a "father".