"Quincy / Kono Yo no Shirushi" is BoA's 13th Japanese single. "Kono Yo no Shirushi" is the song featured on Calpis commercial. This single was not included on any of her full studio albums but was on her best selling compilation album Best of Soul, which was also her second highest selling album.
Read more about Quincy / Kono Yo No Shirushi: Track Listing, Charts