Yuzu is a Japanese popular music duo. Its members are Kitagawa Yujin and Iwasawa Kouji . Both of the band members come from Yokohama in Kanagawa Prefecture. They were discovered as popular street musicians. At first their band name was Lights but Kitagawa thought that name was too hick so they changed the name Yuzu. At that time Kitagawa was eating a Yuzu sherbet so he named their band after it. Incidentally Iwasawa ate vanilla ice cream. Perhaps the band name might have been Vanilla. Sometimes Iwasawa tells this story. The fans of Yuzu are called Yuzukko. In Jan 9 2013 They released their 37th single REASON The 1st track REASON Used as the 3rd ending theme song for Hunter x Hunter 2011 anime. And as the theme song for the film Hunter x Hunter: Phantom Rouge