Kazuo Tsuzura

Kazuo is from the Tsuzura Family, one of the Hundred Families, bearing the number Twenty 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.

(Source: Mahouka Koukou no Rettousei Wikia)