Code Geass: Lelouch of the Rebellion (2006)

S1E9 Refrain

The story unfolds primarily through Kallen's eyes, shedding light on her tumultuous relationship with her birth mother. The Black Knights embark on a mission to eliminate the drug known as "Refrain," gaining significant popularity among the Elevens in the process. During their operation, Kallen discovers her mother among the users of Refrain, leading to her arrest after the Black Knights successfully dismantle the drug's stockpiles. Kallen vows that by the time her mother is free, she will have transformed the world around them.