The outer edge of our symbol, which at first glance appears to be a flower, is actually Yata no kagami, which symbolizes wisdom or honesty,
Yata no Kagami, or "The Mirror Yata" or "The Octagonal Mirror". According to the mythical history of Japan, the Gods offered three sacred gifts to the first japanese emperor to prove his "divine descendence":
1. KUSANAGI NO TSURUGI - "The Sword Kusanagi"
2. YASAKANI NO MAGATAMA - "The Jewel Yasakani"
3. YATA NO KAGAMI - "The Mirror Yata"
Of course Emporor Hirohito was forced to admit the falshood of this divinity to the masses of Japan by General McArthur, after the defeat of the Land Of The Rising Sun in WW2.
The form is modeled after an ancient 8-sided copper mirror (called yata-no-kagami). This mirror is chronicled in Japanese Shinto legends and the shape is represented in numerous Japanese crests (mon). The mirror, reflecting everything truthfully, is a symbol for honesty.
The Yata no Kagami is not a normal mirror. Unlike normal mirrors that reflect our external image, Yata no Kagami reflects our soul. For this reason, there are always mirrors inside Shinto temples (it is said the original Yata no Kagame still remains untouched inside a Shinto temple in Japan).
The shape = octagonal, is seen in the Chinese eight diagrams “ Pa Kwa,” and is popular replete with mirror in the Fanshuei that is used today in the decorating of so many homes and businesses.
To me, it symbolizes that if you want the honest truth, look in the mirror.