B'z is Tak Matsumoto (?? ??, Matsumoto Takahiro ;production, composition & guitar) and Koshi Inaba (?? ?? Inaba Koshi lyrics, vocals). They are known in Japan in being the most successful Japanese rock band ever by selling over 79.3 million of records only in Japan. Since their single " ???Komachi Angel" (Taiyou No Komachi Angel), all their releases have debuted at #1 on the charts.