At the beginning and throughout the series, we see that Tokaku's mom doesn't want her daughter to become a killer like her. Even on her deathbed, she begged her sister to not let Tokaku become a killer. But why did Tokaku's mom do 2 things; 1) Prevent Tokaku from killing and 2) Beg her sister to not let Tokaku become a killer like the rest of the Azuma family/clan? (The image is little Tokaku and her Aunt which we see in Episode 9)