It is believed that the term stems from the usage of the terms shiroboshi (lit: white star) to designate a bout victory, and kuroboshi (black star) to designate a bout defeat. Thus, a "gold star" designates it as a special victory.
The word kinboshi first came into popular use in the Taishō period (1912-1926), and the system of monetarily awarding a maegashira who defeated a yokozuna in an official tournament began in January, 1930.
A kinboshi victory increases the balance in the maegashira's mochikyūkin account by 10 yen. This balance is converted using a multiplier, presently 4,000, and added to the wrestler's bonus in every subsequent tournament in which he competes as a sekitori. With six tournaments a year, this one victory corresponds to a pay increase of 240,000 yen per annum for the remainder of the wrestler's sekitori career.
Kinboshi are not awarded to san'yaku ranked wrestlers who defeat a yokozuna, nor is it awarded if the maegashira beats a yokozuna with a default win (or fusenshō). It is also not given if the yokozuna is disqualified for using an illegal move (or hansoku).
Ginboshi (銀星 or silver star) is also used informally to denote a maegashira victory over an ōzeki. However, there is no monetary bonus for such a win, nor are official ginboshi records kept. The unofficial record holder is Aminishiki, with 45 as of November 2014.
The term kinboshi is used outside sumo in informal language. It can mean a major victory, or (in slang) a beautiful woman.
List of kinboshi records
Tables for both kinboshi earned (by maegashira) and those conceded (by yokozuna) are given below.
Kinboshi appearing in individual wrestlers' records before they began to be awarded in January, 1930 are unofficial and historically conferred.
List of top kinboshi earners
Kinboshi earned by active wrestlers
This is a running list of the number of all kinboshi earned by all currently active wrestlers.
All time kinboshi earned by wrestlers
This list includes the top kinboshi earners since records began, all of whom are currently inactive.
Active yokozuna kinboshi ratio
This is a running list of kinboshi ratio conceded by the currently active yokozuna.
All time lowest kinboshi ratio
This list has the top five yokozuna who have conceded the lowest ratio of kinboshi since official records began. Active yokozuna are listed in bold.