Kigo (to write with a brush) (揮毫)
Kigo, or 揮毫 in Chinese characters, means writing words or phrases with brushes. The word derived from a Japanese phrase, 'fude o furuu' (毫を揮う, meaning to wield a writing brush).
Celebrities and calligraphers often write the saying and draw words on the sign on request. Many of these calligraphies are traded at a high price by those who write with brushes. Writings by the emperors and imperials are called 'ofude' and treated with respect.