How many are there in Quanzhen Qizi?
Ma Yu (Danyangzi), Qiu Chuji (Changchun Zi), Tan Chuduan (Changzhenzi), Wang Chuyi (Yuyangzi), Hao Datong (Taikoo Zi), Liu Chuxuan (Changshengzi), and Ma Yu's wife Sun Buer (a quiet and scattered person) are called the Northern Seven Sons, which is what we usually call "Quanzhen Seven Sons".