In the mid-Edo period, a cheerful young girl named Obun lives with her grandfather and helps run his bookstore. Known for her exceptional drawing skills that rival those of adults, she has earned the nickname Kakimushi, which translates to drawing bug. Obun has a deep love for kibyoshi, a popular literary genre that blends pictures and stories. Despite her lively personality, she harbors a profound loneliness caused by being separated from her mother, a woman who once worked as a prostitute in the floating world.

O-Fumi is the only daughter of a librarian and lives happily with her grandfather until he is unjustly imprisoned. Determined to rescue him, she heads toward the prison to begin a new chapter in her life wielding her paintbrush. The narrative follows Obun as she steps into the dangerous and complex Yoshiwara red-light district, a world from which her mother came, in search of answers and a reunion after an incident occurs at her family's bookstore.

Yoshiwara no Kakimushi is a historical drama that follows a young artist navigating the rigid social structures of Edo-period Japan. Armed with only her artistic talent, Obun must confront the realities of the pleasure quarters and uncover the circumstances that led to her family being torn apart. The story explores themes of artistic expression, family bonds, and survival as a girl known as the drawing bug fights to rewrite her fate and save the people she loves.