What is the most popular fashion brand in Japan?

I'm curious to know, what do you think is the most popular fashion brand in Japan at the moment? Is it a local brand that has captured the hearts of the Japanese public, or perhaps an international brand that has managed to gain a strong foothold in the country? What sets this brand apart from its competitors, and what are some of the key factors that have contributed to its popularity? I'd love to hear your thoughts on this matter.