Bessatsu Margaret , or Betsuma (別マ) for short, is a shōjo manga magazine published monthly in Japan by Shueisha since 1964. The stories featured in it are noted to have an emphasis on character growth, focusing on themes of interpersonal relationships and settings of everyday life.

Shueisha Inc. is a Japanese publishing company headquartered in Chiyoda, Tokyo, Japan. Shueisha is the largest publishing company in Japan. It was established in 1925 as the entertainment-related publishing division of Japanese publisher Shogakukan. The following year, Shueisha became a separate, independent company.