Most people associate the mirror that accompanies a ‘kamidana’ shine in the dojo as just an obscure Shinto-related object, whose true meaning was perhaps lost generations ago. Yet, others have heard of its association to the legend of Amateru and his sacred mirror, the ‘Yata no Kagami, said to be kept at the Ise Shrine in Ise City, Honshu, Japan. Still, the deeper truth, according to such ancient records as the Hotsuma Tsutae, is that the ‘kagami’ is actually a figurative device for examining the ‘light’ (goodness) and ‘dark’ (corruption) inside oneself, In other words, it physically embodies a philosophy of self-examination. ‘Kagami’ translates as ‘see light and dark’ (ka = light, ga = its counterpart, darkness. and mi = see). In studying martial arts, this ‘examining’ becomes a vital aspect of one’s daily practice; searching and adjusting one’s soul, behavior, and actions to stay on a proper path of just, righteous, and harmonious living in society.