Meanings

three-times-three exchange of nuptial cups

six-three-three-four system of education (six years of elementary school, three years each of junior and senior high school and four years of university)

six-three-three-four system of education (six years of elementary school, three years each of junior and senior high school and four years of university)

wild ginger trefoil family crest (of the Tokugawa clan)

something can be learned from anyone

spherical trigonometry

division into three

measure twice and cut once

the non-paying lodger asks for a third helping of rice with much hesitation

unlucky day for starting construction of a house (which would result in a fire that spreads to three adjacent houses)

three times

tanka

three lifetime commandments (youth's femininity, middle-aged struggle, old-age gain)

triple valve

three principles on transfer of defense equipment and technology

one metropolis and three prefectures (i.e. the Tokyo area: Tokyo, Kanagawa, Chiba and Saitama)

Magi

a woman's three obediences (father, husband and son; according to Buddhist and Confucianist teachings)

three legs

a woman has no home of her own in this world (because she has to obey her parents when she is young, her husband when she gets married, and her children when she is old)