This is a list of recording artists who have reached number one on the Billboard Japan Hot 100 chart. Billboard Japan began ranking the Japanese music market on the week ending January 21, 2008. * All acts are listed alphabetically. * Solo artists are alphabetized by last name, groups by group name excluding "A", "An" and "The". * Each act's total of number one Hot 100 hits is shown after their name. * All artists who are mentioned in song credits are listed here; this includes one-time pairings of otherwise solo artists and those appearing as "featured" (for example, for "It's All Love!", both Kumi Koda and Misono receive a mention each). * Artists associated with a group who reached number one, yet have their own solo page in Wikipedia are not listed here, unless they hit number one