Tsuzura Kazuo (廿楽 計夫) is from the (廿楽) Family, one of the , bearing the number Twenty (Tsu) in his name. The Tsuzura and Isori Families both produced many exceptional researchers who freely exchanged research findings and remained national authorities in the field. Even Hattori's favored Compound Magic bore fruit after tutelage under Tsuzura-sensei.