Ribon is a monthly Japanese shōjo manga magazine published by Shueisha on the third of each month. First issued in August 1955, its rivals are Nakayoshi and Ciao. It is one of the best-selling shōjo manga magazines, having sold over 590 million copies since 1978. Its circulation was in the millions between 1987 and 2001, peaking at 2.3 million in 1994. In 2009, the magazine's circulation was 274,167. In 2010, the circulation dropped to 243,334.