This article explores the significance of blue in Japanese culture, from its historical origins in the Heian period (794–1185) to its current relevance in fashion and branding. Blue is associated with positive qualities such as trustworthiness, reliability, serenity, purity and cleanliness. It is also seen as a symbol of peace and harmony and is believed to bring good luck and ward off evil spirits. The color has become popular among Japanese people due to its association with these qualities, leading many businesses and brands to adopt it for their logos or product packaging designs. Blue is also widely used in fashion across Japan, particularly among younger generations.