Kōsaka Aki is a fictional character from the anime series Ore no Imōto ga Konna ni Kawaii Wake ga Nai, also known as My Little Sister Can't Be This Cute. She is the younger sister of the protagonist, Kōsaka Kyōsuke, and is known for her strong personality and passion for anime and video games. Aki often displays a tsundere character type, showing a mix of affection and hostility towards her brother. In the series, Aki's character development revolves around her relationships with her brother and friends, as well as her struggles with social acceptance. Her interests in otaku culture and her secretive nature about her hobbies create comedic and heartfelt moments throughout the story. Aki's character has become popular among fans for her relatable traits and unique charm.