Year 24 Group

Year 24 Group (24年組) refers to one of two female manga artist groups which are considered to have revolutionized shōjo manga (girls' comics). Their works often examine "radical and philosophical issues", including sexuality and gender issues, and many of their works are now considered "classics" of shōjo manga. Many of those in the first group, Year 24 Flower Group (花の24年組), also known as the Forty-Niners, were born in Shōwa 24 (1949). The exact membership is not precisely defined, but includes Yasuko Aoike, Moto Hagio, Riyoko Ikeda, Yumiko Ōshima, Keiko Takemiya, Toshie Kihara, Ryoko Yamagishi, Minori Kimura, Nanae Sasaya, and Mineko Yamada. A second group, known as Post Year 24 Group (ポスト24年組), includes Wakako Mizuki, Michi Tarasawa, Aiko Itō, Yasuko Sakata, Shio Satō, and Yukiko Kai.

The Year 24 Group significantly contributed to the development of subgenres in shōjo manga, and marked the first major entry of women artists into manga. Thereafter, shōjo manga would be drawn primarily by women artists for an audience of girls and young women. The Year 24 Group used bildungsroman genre conventions in their works. Stylistically, the Year 24 Group created new conventions in panel layout by departing from rows of rectangles that were the standard of the time and using panel shape and configuration to convey emotion, and softening or removing panel borders.

Moto Hagio and Keiko Takemiya lived in the same apartment in Ōizumi in Nerima, Tokyo from 1970 to 1973, in a situation similar to Osamu Tezuka's Tokiwa-so. Takemiya's friend Norie Masayama lived nearby and was described by Moto Hagio as Takemiya's "brain staff". Masayama was not a mangaka herself, but she introduced Takemiya to male homosexuality for women via Barazoku and Les amitiés particulières, which inspired Takemiya and Hagio to create shōnen-ai works. Until that time, shōjo manga was written mainly by male manga artists, such as Osamu Tezuka with his Princess Knight, and their attempts by female manga artists to write manga for girls were relatively new. Fortunately their manga were welcomed by girls, women, and men. Their actions and success paved the way for the appearances of many female manga artists like Rumiko Takahashi.

Comiket, the world's largest comic convention, was started by the dojinshi circle Meikyu (迷宮), which began as a group for studying the works of Moto Hagio.

Works by Hagio and Satō were included in the shōjo manga anthology Four Shōjo Stories, published in North America by Viz Communications in 1996.