Chidokan mark

From the Chidokan NZ training manual:

"The outside circle, coloured red, expresses perfection and symbolises the infiniteness of the Universe.

The red colour of the inner circle represents strength (power) and passion (inner fire, or spirit).

The character KU inscribed inside this inner circle was chosen and used by the founder of Japanese karatedo, Master Funakoshi Gichin Sensei. Simply translated, KU means void or emptiness, and is the symbol of ‘moving Zen’. However, the Zen influence would suggest the essence of KU is considered to lie within passion and strength - with the object being to conceal these attributes.

The inner circle, having the character KU, is regarded as the heart, trying without rest to approach a state of perfection. Thus, the two circles are close in proximity, but never touch. That is to say, even though it is impossible to reach this ideal (perfection), we aim to do so, by striving along the path every day."

Markr; Flickr.