Taishou Yakyuu Musume.

Taishou Yakyuu Musume, written by Kagurazaka Jun, originated as a light novel series that debuted in 2007. Set in the Taisho era of Japan, the narrative focuses on a group of young women who decide to challenge a boys' baseball team, reflecting the social shifts and the early waves of feminist consciousness occurring in Japan during the 1920s. The work is notable for its historical atmosphere and its blending of traditional period aesthetics with the burgeoning interest in Western sports culture.

The series was illustrated by Copple, whose character designs were praised for capturing the distinct period-accurate fashion of the Taisho era while maintaining the expressive style characteristic of contemporary light novels. Following its success in print, the story was adapted into a television anime series in 2009 by J.C.Staff. The franchise is recognized by collectors primarily for its gentle exploration of gender roles and its detailed commitment to the historical setting of early 20th-century Tokyo.