Aika Kakeyama is from a doujin "Double standard girls are incomprehensible". She is an Animal Rights Activist, and a member of the Wildlife Conservative Association, who posts animal protection propaganda on social media. In the original doujin, she was killed and eaten by a bear when she was trying to take a leak after finding out that the restrooms were out of order. But in this version, you'll get to save her from the bear...